As HINT1 has been previously described as a tumor suppressor in several cancer cells and as an inhibitor of β-catenin activity in colon cancer and melanoma2, this study examined the physiological roles of the constitutive deacetylated HINT1 mutant (HINT1 2KR) in tumorigenesis in DLD1 and SW480 cell lines. The gene discussed is HINT1; the disease is neoplasm.