CLPP and cancer: Overall, these studies suggest that: (1) cellular stress contributed to the anti-tumorigenic effects of ONC201 in addition to apoptosis and G1 cell cycle arrest in OC cells (37, 51), and (2) ClpP activation is partially responsible for the anti- tumorigenic activity of ONC201, and activation of ClpP provides a targeted approach to activate ER stress in cancer cells (52).