The antagonism of the Wnt/β-catenin pathway by 1,25(OH)2D3 has been described in several solid cancers as a consequence of a variety of mechanisms: (1) by promoting the lysosomal degradation of LRP6, a member of the Wnt surface receptor complex, in pancreatic adenocarcinoma cells [87]; (2) via ligand-activated VDR-β-catenin interaction in renal carcinoma cells [88] and mouse skin tumorigenesis [89,90]; and (3) via ligand-activated VDR-β-catenin interaction and DKK-1 induction in Kaposi’s sarcoma cells [91]. Here, VDR is linked to Kaposi's sarcoma.