Collectively, the ability of NDI1 to decrease the sensitivity of NCI-HCC cells to GPX4 inhibition—and the ability of piericidin to sensitize Nthy-ori 3-1 cells to GPX4 inhibition—provides gain-of-function and loss-of-function evidence that causally links complex I loss to lipid peroxide sensitivity. Here, AVPR2 is linked to hepatocellular carcinoma.