XIAP and glioma: TNFSF13 has an antiapoptotic effect in death ligand-induced apoptosis in a glioma cell line and has been associated with enhanced levels of XIAP, a member of the inhibitor of apoptosis (IAP) family that prevents cell death by directly inhibiting caspase activity [36]. XIAP was specifically upregulated in human MII oocytes. TNFSF13 overexpression in human oocytes was reported previously [17, 37], and it can have both proapoptotic and antiapoptotic functions, according to the used cell line [38, 39].