HLA-DRB1 and multiple sclerosis: Studies involving HLA-DRB1 have found a link between innate and T-cell-mediated immunity [78, 79], and results obtained from a multiple sclerosis study show that the presence of a VDRE (vitamin D response elements) in the proximal promoter region of the HLA-DRB1 gene increased gene expression and imparts 1,25-(OH)2-D3 (Vitamin D) sensitivity to the DRB1*15:01 allele [79].