Our recent studies have revealed several non-apoptosis-related functions of XIAP via its RING domain, including the upregulation of cyclin D1, while promoting bladder cancer cell growth [18], and the promotion of F-actin formation and colon cancer cell invasion via inhibition of SUMOlation of RhoGDIα (Rho GDP-dissociation inhibitor α) at lys-138 [53]. Here, XIAP is linked to malignant colon neoplasm.