FOXP3 and Huntington disease: We further found that CD4+CD45RA+T cells were the major population reacting to the 1,25(OH)2D in HD, as 1,25(OH)2D significantly inhibited IL-17 and promoted Foxp3 expression on CD4+CD45RA+T cells than CD4+CD45RA−T cells (Figure 5(b)).