CYCS and malignant colon neoplasm: During apoptosis, proapoptotic multidomain Bcl-2 family proteins, Bax and Bak, oligomerize on mitochondria to form channels on mitochondrial membrane causing the leakage of apoptogenic proteins such as cytochrome c. 12, 13, 14, 15 To investigate the impact of Bax deficiency in DNA-damage-induced apoptosis, we evaluated Dox-induced apoptosis in isogenic Bax-deficient HCT116 colon cancer cells.