Exhibit 32.1

CERTIFICATION PURSUANT TO

18 U.S.C. §1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the accompanying Annual Report on Form 10-K of Celgene Corporation ("the Company") for the year ended December 31, 2018 ("the Periodic Report"), I, Mark J. Alles, Chief Executive Officer of the Company, hereby certify pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, to the best of my knowledge that the Periodic Report fully complies with the requirements of Section 13 (a) or 15 (d) of the Securities Exchange Act of 1934 and that the information contained in the Periodic Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

Date:	February 26, 2019	/s/ Mark J. Alles
		Mark J. Alles   Chief Executive Officer