BIRC2 and cancer: Although several other survival proteins such as Bcl2 and BclxL are known to play roles in regulating tumor cell survival and chemoresistance in cancer cells during HA-CD44 binding (147), the involvement of cIAP-1, cIAP-2, and XIAP in promoting HA/CD44-mediated tumor cell survival and drug resistance has only recently received some attentions.