PTGS2 and colorectal cancer: Indeed, the analysis of Wnt, β-catenin, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB), cyclooxygenase-2 (COX-2), dickkopf-related protein (DKK-1) and cyclin dependent kinase inhibitor 1A (CDKN1A, also known as p21) messenger tissue expression revealed a significant reduction when rats with AOM-induced colorectal cancer received combined treatment of paricalcitol and 5-FU, compared to treatment with 5-FU alone [122].