reported that 1‐MNA can stabilize SIRT1 by decreasing its ubiquitination.[20] One recent study found that 1‐MNA could induce T cells to secrete the tumor‐promoting cytokine tumor necrosis factor α (TNFα) in human ovarian cancer.[21] All these studies substantiated cancer‐promoting role of NNMT and the biological activity of its metabolite, 1‐MNA. The gene discussed is NNMT; the disease is ovarian carcinoma.