While the immunosuppressive effects of VD3 may offer potential benefits in cancer treatment;11 some researchers suggest these same properties could also be detrimental.12,13 Lymphocytes express the vitamin D receptor (VDR) upon activation, while dendritic cells and macrophages express it constitutively, making VD3 a key modulator of immune and inflammatory responses.1,12,14 Moreover, Th17 lymphocytes express VDR, and the proinflammatory cytokine IL-17A is modulated by VD3 in both mouse and human T lymphocytes. The gene discussed is IL17A; the disease is cancer.