In colon cancer and melanoma cells, deacetylation by SIRT1 promotes tumor suppressor activity by enhancing the ability of histidine triad nucleotide-binding protein 1 (HINT1) to bind to β-catenin or MITF, resulting in an increase in the tumor suppressor function of HINT1123. The gene discussed is SIRT1; the disease is malignant colon neoplasm.