Taken together, these data demonstrate that p53-mediated downregulation of SLC7A11 is induced in the cells and tissues of p533KR/3KRXrcc4−/− mice and also suggest that p53-mediated ferroptosis may play a role in both preventing tumor development and testicular atrophy observed in the p533KR/3KRXrcc4−/− mice. The gene discussed is TP53; the disease is neoplasm.