However, we have recently found that the human cytomegalovirus downregulates the vitamin-D receptor (VDR) during infection [13], thus conferring cellular resistance to bioactive vitamin D. Additionally, VDR levels were found to be generally reduced in the blood cells of hematopoietic stem-cell transplant patients undergoing active HCMV infection [14]. This evidence concerns the gene VDR and cytomegalovirus infection.