GDC-0152 is a potent small-molecule antagonist of inhibitor of apoptosis (IAP) proteins, including ML-IAP, XIAP, cIAP1 and cIAP2, that binds to the BIR domain of ML-IAP and the BIR3 domains of XIAP, cIAP1 and cIAP2 with values of inhibition constant Ki of 14 nM, 28 nM, 17 nM and 43 nM respectively. GDC-0152 potentially inhibits tumor growth of breast cancer by promoting cIAP1 degradation and inducing caspase-3/7 activation which result in the decreasing of cell viability of breast cancer cells with normal epithelial cells unaffected. In recent studies, GDC-0152 shows its ability to disrupt the binding of XIAP to caspase-9 and the association of ML-IAP, cIAP1 and cIAP2 with Smac in HEK293T cells.