X0306 4 2016-02-18 0 0000913077 AFFYMETRIX INC AFFX 0001577539 Wood Gavin C/O AFFYMETRIX, INC. 3420 CENTRAL EXPRESSWAY SANTA CLARA CA 95051 0 1 0 0 EVP, Chief Financial Officer Common Stock 2016-02-18 4 A 0 26504 0 A 142136 D Common Stock 2016-02-19 4 F 0 3741 13.98 D 138395 D Common Stock 2016-02-19 4 F 0 1278 13.98 D 137117 D This Form 4 does not include 26,504 performance-based restricted stock units granted on February 18, 2016. These shares will be reported on subsequent Form 4s if and when the performance criteria are met. Restricted stock units vest in equal annual installments over four years from the grant date of February 18, 2016. Represents the number of shares withheld by Affymetrix, Inc. to cover the tax liability of resulting from the scheduled vesting of performance restricted stock units previously granted. Represents the number of shares withheld by Affymetrix, Inc. to cover the tax liability of resulting from the scheduled vesting of restricted stock units previously granted. /s/ Siang H. Chin, Attorney-in-Fact for Gavin Wood 2016-02-22