Etoposide-induced ROS production may modulate mitochondrial function causing loss of mitochondria membrane potential and leakage of proapoptotic proteins cytochrome c, second mitochondria-derived activator of caspases, and AIF from mitochondria.2, 5, 6 These proapoptotic proteins may initiate different apoptotic signaling causing demise of cancer cells. The gene discussed is PROS1; the disease is cancer.