PTGS2 and rectal neoplasm: A single gene was induced by calcitriol in rectal tumor organoids, but repressed in normal rectum organoids (MUC5B), while the opposite regulation was found for S100G, FREM1, NPSR1, and PTGS2. In addition, COLEC12; LINCO810; and the metabolizing enzymes CYP24A1, CYP2B7P, and CYP2B6 were induced to a lesser degree in rectal tumor organoids, whereas TRPV6 and CYP3A4 were more strongly induced by calcitriol in rectal tumor organoids (Figure 6a).