VDR and neoplasm: The fact that the VDR knockdown cells are insensitive to treatment with 1,25(OH)2D3 is particularly relevant to the in vivo experiments, as these were performed in vitamin D-replete mice, thus providing evidence that the reduction in tumor growth seen in vivo with VDR-KD cells must be independent of vitamin D. Taken together, our findings indirectly suggest that the VDR holds hitherto unknown functions that promote cancer cell growth independent of its ligand.