IL-2 signaling increases with expression of CD25 [7,8] and a previous study by Cerosaletti et al. reported that homozygous carriers of MS-associated IL2RA risk allele for SNP rs2104286 had reduced IL-2 receptor signaling as assessed by STAT5 phosphorylation in CD25hi and memory CD4+ T cells [40]. This evidence concerns the gene CD4 and myeloid sarcoma.