VDR and chronic kidney disease: Shi et al. (2016) demonstrated that the dysfunction of BM-EPCs observed in patients with PGF is closely associated with the activation of p38 MAPK, emphasizing the crucial role of MAPKs in the pathogenesis of PGF. The study conducted by Wu-Wong et al. (2010) demonstrated that activation of the VDR enhances endothelial function in patients with chronic kidney disease. The levels of VDR were generally observed to be decreased in the blood cells of patients undergoing active HCMV infection following hematopoietic stem-cell transplantation (Robak et al., 2021).