Interestingly, we observed that prostate cancer cells expressing low (PC3) or mutant (DU145) RB (Figure 1E) required lower doses of RSL3 to reach a similar level of cell death (Figure 1, A–D), were more sensitive to RSL3-induced ferroptosis (Figure 1F), and displayed higher levels of associated lipid peroxidation (Figure 1G). This evidence concerns the gene RB1 and prostate cancer.