Huh‐7, Hep3B, and HCC primary cell line were treated with increasing concentration of a glutamate–cystine antiporter system Xc− inhibitor (erastin), and found that USP20 depletion inhibited the viability of HCC cells, and cells depleted with USP20 were more sensitive to ferroptosis induced by erastin treatment (Figures 2A–C and S2E). Here, USP20 is linked to hepatocellular carcinoma.