Compared with parental cells, KO of PRDX6 significantly reduced the half‐life of NNMT protein (Figure4A), whereas ectopic expression of PRDX6 markedly prolonged the half‐life of NNMT protein in ovarian cancer cells (Figure S5A, Supporting Information), suggesting that PRDX6 enhances the protein stability of NNMT. The gene discussed is NNMT; the disease is ovarian carcinoma.