SC 14D9/A

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

SCHEDULE 14D-9

SOLICITATION/RECOMMENDATION STATEMENT

PURSUANT TO SECTION 14(d)(4) OF THE

SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 4)

VENTANA MEDICAL SYSTEMS, INC.

(Name of Subject Company)

VENTANA MEDICAL SYSTEMS, INC.

(Name of Person Filing Statement)

Common Stock, Par Value $0.001 Per Share

(Title of Class of Securities)

92276H106

(CUSIP Number of Class of Securities)

Christopher M. Gleeson

President and Chief Executive Officer

VENTANA MEDICAL SYSTEMS, INC.

1910 E. Innovation Park Dr.

Tucson, AZ 85755

Telephone (520) 887-2155

Toll Free (800) 227-2155

Fax (520) 229-4207

(Name, Address and Telephone Number of Person Authorized to Receive

Notice and Communications on Behalf of the Person Filing Statement)

COPIES TO:

Thomas A. Cole Fredrick C. Lowinger Michael A. Gordon Robert L. Verigan Sidley Austin LLP 1 South Dearborn Street Chicago, IL 60603 Telephone (312) 853-7000 Fax (312) 853-7036 Daniel M. Mahoney Snell & Wilmer L.L.P. One Arizona Center 400 E. Van Buren Phoenix, AZ 85004 Telephone (602) 382-6000 Fax (602) 382-6070

¨ Check the box if the filing relates solely to preliminary communications made before the commencement of a tender offer

Purpose of Amendment

The purpose of this amendment is to amend Item 9—Exhibits by adding new exhibits (a)(10), (a)(11) and (a)(12) and revising the Exhibit Index accordingly.

Item 9. Materials to Be Filed as Exhibits.

Exhibit No.	Document
(a)(1)	Letter to the Company’s stockholders dated July 11, 2007*(1)
(a)(2)	Press release issued by the Company on July 11, 2007(1)
(a)(3)	Letter to the Company’s employees dated July 11, 2007(1)
(a)(4)	Employee/customer/supplier “Frequently Asked Questions” (1)
(a)(5)	Press release issued by the Company on July 19, 2007(1)
(a)(6)	Investor presentation materials for Earnings Conference Call held on July 20, 2007(1)
(a)(7)	Transcript of Earnings Conference Call held on July 20, 2007(1)
(a)(8)	Press release issued by the Company on July 26, 2007(1)
(a)(9)	Letter to the Company’s employees dated July 26, 2007(1)
(a)(10)	Press release issued by the Company on August 21, 2007
(a)(11)	Letter to the Company’s employees dated August 21, 2007
(a)(12)	Letter to the Company’s employees dated August 22, 2007
(e)(1)	Excerpts from the Company’s Definitive Proxy Statement on Schedule 14A relating to the 2007 Annual Meeting of Stockholders as filed with the SEC on March 28, 2007(1)
(e)(2)	1988 Stock Option Plan and forms of agreements thereunder (Incorporated by reference to Exhibit 10.7(A) to the Company’s Registration Statement on Form S-l (SEC File No. 333-4461), declared effective by the SEC July 26, 1996)
(e)(3)	1996 Stock Option Plan and forms of agreements thereunder (Incorporated by reference to Exhibit 10.7(B) to the Company’s Registration Statement on Form S-l (SEC File No. 333-4461), declared effective by the SEC July 26, 1996)
(e)(4)	1996 Employee Stock Purchase Plan (Incorporated by reference to Exhibit 10.8(B) to the Company’s Registration Statement on Form S-l (SEC File No. 333-4461), declared effective by the SEC July 26, 1996)
(e)(5)	1996 Directors Option Plan (Incorporated by reference to Exhibit 10.8(C) to the Company’s Registration Statement on Form S-l (SEC File No. 333-4461), declared effective by the SEC July 26, 1996)
(e)(6)	1998 Nonstatutory Stock Option Plan and forms of agreements thereunder (Incorporated by reference to Exhibit 4.1 to the Company’s Registration Statement on Form S-8 (SEC File No. 333-92883), filed with the SEC on December 16, 1999 and Exhibit 4.1 to the Company’s Registration Statement on Form S-8 (SEC File No. 333-105976), filed with the SEC on June 10, 2003)
(e)(7)	2001 Outside Director Stock Option Plan (Incorporated by reference to Exhibit 4.1 to the Company’s Registration Statement on Form S-8 (SEC File No. 333-69658), filed with the SEC on September 19, 2001)

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(e)(8)	2005 Equity Incentive Plan (Incorporated by reference to the Company’s Definitive Proxy Statement on Schedule 14A (SEC File No. 000-20931) filed with the SEC on March 31, 2005)
(e)(9)	2005 Employee Stock Purchase Plan (Incorporated by reference to the Company’s Definitive Proxy Statement on Schedule 14A (SEC File No. 000-20931) filed with the SEC on March 31, 2005)
(e)(10)	2005 Equity Incentive Plan Agreement (Incorporated by reference to Exhibit 10.8.1 to the Company’s Annual Report on Form 10-K (SEC File No. 000-20931) filed with the SEC on February 16, 2007)
(e)(11)	2005 Equity Incentive Plan Agreement (Accelerated Vesting) (Incorporated by reference to Exhibit 10.8.2 to the Company’s Annual Report on Form 10-K (SEC File No. 000-20931) filed with the SEC on February 16, 2007)
(e)(12)	Preferred Share Rights Agreement, dated as of May 6, 1998 between the Company and Norwest Bank Minnesota, N.A., including the Certificate of Designations, the form of Rights Certificate and the Summary of Rights attached thereto as Exhibits A, B and C, respectively (Incorporated by reference to Exhibit 1 to the Company’s Registration Statement on Form 8-A12G filed with the SEC on June 9, 1998)
(e)(13)	Restated Certificate of Incorporation of the Company (Incorporated by reference to Exhibit 3.1(i)(a) to the Company’s Registration Statement on Form S-l (SEC File No. 333-4461), declared effective by the SEC July 26, 1996)
(e)(14)	Certificate of Amendment to Certificate of Incorporation (Incorporated by reference to Exhibit 3.3 to the Company’s Quarterly Report on Form 10-Q (SEC File No. 000-20931), filed with the SEC on July 26, 2005)
(e)(15)	Form of Indemnification Agreement for directors and officers (Incorporated by reference to Exhibit 10.6 to the Company’s Registration Statement on Form S-l (SEC File No. 333-4461), declared effective by the SEC July 26, 1996)

* Included in materials mailed to the Company’s stockholders.

⁽¹⁾ Previously filed with Schedule 14D-9 or an amendment thereto.

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SIGNATURE

After due inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete, and correct.

VENTANA MEDICAL SYSTEMS, INC.
By:	/S/    MARK D. TUCKER
	Mark D. Tucker
	Senior Vice President, General Counsel

Date: August 22, 2007

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EX-99.(A)(10)

Exhibit (a)(10)

VENTANA MEDICAL SYSTEMS, INC.	FOR IMMEDIATE RELEASE
1910 E. Innovation Park Drive
Tucson, Arizona 85755
(520) 887-2155

VENTANA RESPONDS TO SECOND EXTENSION OF ROCHE’S

UNSOLICITED TENDER OFFER

Tucson, Ariz., August 21, 2007—Ventana Medical Systems, Inc. (NASDAQ: VMSI), the global leader in tissue-based cancer diagnostics, today issued the following statement regarding Roche’s decision to once again extend its unsolicited tender offer to acquire all outstanding shares of Ventana for $75.00 in cash per common share:

“We remain steadfast in our position that Roche’s offer is wholly inadequate and our Board of Directors continues to recommend that stockholders not tender any of their shares to Roche. Roche’s offer remains significantly below our current stock price, even with the recent tumultuous market conditions, proving that the market agrees that the offer fails to reflect the inherent value of the Company, its steady growth momentum, and the magnitude of the synergies that would be unlocked in a combination with Roche. Ventana is an extraordinary company which, given the increasing focus on and significant value of companion diagnostics to pharmaceutical companies, is uniquely poised to benefit from the potential in the future of personalized medicine.”

ABOUT VENTANA MEDICAL SYSTEMS, INC.

Ventana develops, manufactures, and markets instrument/reagent systems that automate tissue preparation and slide staining in clinical histology and drug discovery laboratories worldwide. The Company's clinical systems are important tools used in the diagnosis and treatment of cancer and infectious diseases. Ventana's drug discovery systems are used to accelerate the discovery of new drug targets and evaluate the safety of new drug compounds.

SAFE HARBOR STATEMENT

This press release may contain certain forward-looking statements within the meaning of the federal securities laws. The Private Securities Litigation Reform Act of 1995 provides a safe harbor for forward-looking statements. These forward-looking statements are subject to certain risks and uncertainties that could cause actual results to differ materially from those expected, depending on a variety of factors, such as risks associated with the development, manufacturing, marketing, and sale of medical products, competitive factors, general economic conditions, legal disputes, and government actions. Please refer to our most recent Annual Report on Form 10-K filed with the Securities and Exchange Commission (SEC), and all subsequent SEC filings, for a more detailed discussion of applicable risks and uncertainties.

VENTANA’S STOCKHOLDERS SHOULD READ THE COMPANY’S SOLICITATION/RECOMMENDATION STATEMENT ON SCHEDULE 14D-9, WHICH WAS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION (“SEC”) ON JULY 11, 2007, AND ANY AMENDMENTS OR SUPPLEMENTS THERETO. THE COMPANY’S SOLICITATION/RECOMMENDATION STATEMENT SETS FORTH THE REASONS FOR THE

RECOMMENDATION OF THE VENTANA BOARD AND RELATED INFORMATION. THE SOLICITATION/RECOMMENDATION STATEMENT AND OTHER PUBLIC FILINGS MADE FROM TIME TO TIME BY THE COMPANY WITH THE SEC ARE AVAILABLE WITHOUT CHARGE FROM THE SEC’S WEBSITE AT WWW.SEC.GOV, AT VENTANA’S WEBSITE AT WWW.VENTANAMED.COM OR FROM VENTANA’S INFORMATION AGENT, INNISFREE M&A INCORPORATED AT (888) 750-5834.

Visit the Ventana Medical Systems, Inc., website at www.ventanamed.com.

For Media: Anna Cordasco/Brooke Morganstein Sard Verbinnen & Co. 212-687-8080 For Investors: Brad Wilks/Seth Frank Sard Verbinnen & Co. 312-895-4700   Alan Miller/Jennifer Shotwell Innisfree M&A Incorporated 212-750-5833

EX-99.(A)(11)

Exhibit (a)(11)

To All Ventana Employees,

As you may have heard, Roche once again extended its tender offer for another 30 days.

This extension does not alter the situation and we remain steadfast in our position that Roche’s offer is wholly inadequate. Our Board of Directors continues to recommend that stockholders not tender any of their shares to Roche. Roche’s offer remains significantly below our current stock price, despite the recent tumultuous market conditions, proving that the market agrees that the offer fails to reflect the inherent value of the Company, its steady growth momentum, and the magnitude of the synergies that would be unlocked in a combination with Roche.

As you know, Ventana is an extraordinary company which, given the increasing focus on and significant value of companion diagnostics to pharmaceutical companies, is uniquely poised to benefit from the potential in the future of personalized medicine.

I want to again express my sincere appreciation for your continued efforts and focus on maintaining business as usual.

Best regards,

Chris

VENTANA’S STOCKHOLDERS SHOULD READ THE COMPANY’S SOLICITATION/RECOMMENDATION STATEMENT ON SCHEDULE 14D-9, WHICH WAS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION (“SEC”) ON JULY 11, 2007, AND ANY AMENDMENTS OR SUPPLEMENTS THERETO. THE COMPANY’S SOLICITATION/RECOMMENDATION STATEMENT SETS FORTH THE REASONS FOR THE RECOMMENDATION OF THE VENTANA BOARD AND RELATED INFORMATION. THE SOLICITATION/RECOMMENDATION STATEMENT AND OTHER PUBLIC FILINGS MADE FROM TIME TO TIME BY THE COMPANY WITH THE SEC ARE AVAILABLE WITHOUT CHARGE FROM THE SEC’S WEBSITE AT WWW.SEC.GOV, AT VENTANA’S WEBSITE AT WWW.VENTANAMED.COM OR FROM VENTANA’S INFORMATION AGENT, INNISFREE M&A INCORPORATED AT (888) 750-5834.

EX-99.(A)(12)

Exhibit (a)(12)

To All Ventana Employees:

As you may have seen yesterday an Arizona district court ruled that a state anti-takeover statute was not applicable in Ventana’s situation with Roche. This morning, there has been some inaccurate media coverage on that ruling that we are working to correct.

First, you should know that Ventana has never looked to or referenced the Arizona statute as a defense against Roche. Our view when Roche made its inadequate offer was and remains today that Ventana is worth significantly more than Roche has offered and we will not let them take value for their shareholders that rightly belongs to ours. From our perspective, the Arizona statute is essentially irrelevant to that point and so the court’s decision changes nothing.

Second, some of the articles suggest that the Arizona judge struck down our shareholder rights plan, or as it is commonly known, a “poison pill.” A rights plan is a tool that gives a Board of Directors time to fully evaluate unsolicited offers and to make recommendations that are in the best interests of all shareholders. You should know that the Arizona court definitely DID NOT invalidate our rights plan and it remains very much in place. We are working to correct the error with the reporters who did not understand or who have misinterpreted the Arizona court’s decision.

In closing let me say that our board and management remain firmly of the view that Roche’s offer is inadequate and, given the extremely low count of shares recently tendered into Roche’s offer, it’s clear that the market agrees. We are focused on business as usual and, as we’ve said before, the best way to control our own destiny is to continue performing for our customers. I appreciate your continued support.

Chris