KLRK1 and cancer: Similar observations were made in other cancer types where authors reported that treatment of Panc89 (a pancreatic carcinoma cell line) and PC-3 (a prostate carcinoma cell line) with Valproic acid (VPA), a histone deacetylase inhibitor, significantly enhanced the expression and/or release of the several NKG2D ligands such as ULBP-2, MICA, MICB (23).