Triciferol functions as a multiple ligand with combined VDR agonist and HDAC antagonist activities. Triciferol binds directly to the VDR (IC50=87 nM), and functions as an agonist with 1,25D-like potency on several 1,25D target genes. Triciferol induces marked tubulin hyperacetylation, and augments histone acetylation. Antiproliferative and cytotoxic activities.