The Company leases its facilities and certain equipment. The Company's leases have terms through 2028. The leases of the Company's current primary facilities in Cambridge were extended in 2009 through December 2015. The term of the Kendall Square Lease began on January 1, 2003. Rent payments pursuant to the Kendall Square Lease will be subject to increase in May 2013, based on changes in an inflation index. These increases will be treated as contingent rentals. The Kendall Square Lease will expire in 2018, and the Company has the option to extend the term for two consecutive terms of ten years each. The Company occupies and uses for its operations approximately 120,000 square feet of the Kendall Square Facility. The Company has sublease arrangements in place for the remaining rentable square footage of the Kendall Square Facility, with terms that expire in April 2015 and August 2015. See Note R, "Restructuring Expense," for further information. In 2011, the Company entered into two leases for approximately 1.1 million square feet of office and laboratory space in Boston, Massachusetts. The Company expects that it will begin occupying and making lease payments for this space in late 2013. Please see Note I, "Fan Pier Leases," for additional information regarding this commitment.

As of December 31, 2011, future minimum commitments under Fan Pier Leases, facility operating leases with terms of more than one year and expected sublease income under the Company's subleases for the Kendall Square Facility were as follows:

Year	Fan Pier Leases		Kendall Square Lease		Sublease Income			Other Operating Leases		Total Lease Commitments (Net of Sublease Income)

	(in thousands)
2012	$	—	$	18,260	$	(7,850	)	$	36,455	$	46,865
2013		—		18,260		(8,424	)		37,942		47,778
2014		67,206		18,260		(8,424	)		29,025		106,067
2015		67,206		18,260		(3,942	)		22,678		104,202
2016		67,206		18,260		—			4,611		90,077
Thereafter		887,211		24,346		—			10,018		921,575

Total minimum lease payments	$	1,088,829	$	115,646	$	(28,640	)	$	140,729	$	1,316,564

Rental expense for 2011 was $49.4 million, which included $11.2 million related to the Kendall Square Facility. Rental expense for 2010 was $46.6 million, which included $11.6 million related to the Kendall Square Facility. Rental expense for 2009 was $39.1 million, which included $11.5 million related to the Kendall Square Facility.

In addition, the Company has committed to make potential future milestone and royalty payments pursuant to the Alios Agreement. Payments generally become due and payable upon the achievement of certain developmental, regulatory and/or commercial milestones.

In September 2010, the Company issued $400.0 million in aggregate principal of 2015 Notes. See Note K, "Common Stock Offerings and Convertible Senior Subordinated Notes," for further information.