GPX4 and colorectal carcinoma: Next, treatment of human CRC HCT 116 and HT-29 cells with ferroptosis inducers erastin (a system Xc− inhibitor) [2] or RSL3 (a GPX4 activity inhibitor) [35] reduced cell growth, and the effects were alleviated by the ferroptosis-specific inhibitor ferrostatin-1 (Fer-1, an Fe2+-dependent lipid ROS scavenger [36]; Figure 3a).