XIAP and cancer: Several investigations indicated that NCOA3 increases insulin-like growth factor-I (IGF-I) and epidermal growth factor (EGF) signaling, known upstream regulation signaling of AKT.29 It has been shown that AKT confers drugs resistance in cancer cells by regulating many apoptosis-associated proteins like XIAP and BAD.30 Thus, breast cancer cells resistance to taxol could be involved in activating the IGF-I/AKT or EGF/AKT pathway.