Previous studies in skin suggest that the unliganded VDR plays a role in the context of normal keratinocyte stem cell function (through interaction with the canonical Wnt pathway).20,37,38 The fact that ablation of VDR expression in cancer cells results in a marked inhibition of cell and tumor growth raises the possibility of the unliganded VDR being involved in the regulation of cancer cell proliferation and apoptosis. Here, VDR is linked to cancer.