CFLAR and renal carcinoma: It has also been demonstrated that Withanolide E, a steroidal lactone derived from Physalis peruviana, can highly sensitize renal carcinoma cells and other human cancer cells to TRAIL-mediated apoptosis through the rapid destabilization, aggregation and proteasomal degradation of c-FLIP proteins, confirming the key inhibitory role of c-FLIP in death ligand-mediated apoptosis [26].