We treated control and OTUD5‐KO cells with nutlin‐3a and observed that knockout of OTUD5, in combination with nutlin‐3a treatment, led to a reduction in protein levels of OTUD5 and GPX4 (Figure 5A,B), thereby triggering ferroptosis in cancer cells and consequently inhibiting cell proliferation (Figure 5C,D). The gene discussed is GPX4; the disease is cancer.