CD40 and vitamin D deficiency: In this study, MS patients who had vitamin D deficiency at disease onset exhibited strong association with three SNPs of IL7R; rs987107 (P-value=0.047), rs3194051 (P-value=0.03,) and rs1494571 (P-value=0.036), as well as two polymorphisms within the CD40 gene: rs6074022 and rs1883832 (with a P-value=0.049 for both).