The protein kinase C α (PRKCA) gene is one of few genes reported to be associated with MS in more than one population.5, 6 Recently, the interleukin 7 receptor α chain gene (IL7RA) was found to be associated with MS in two independent candidate gene studies and in a genome-wide association study.7–9 The genome-wide association study also identified variants in the interleukin 2 receptor α chain gene (IL2RA) as risk factors for MS,7 which is in accordance with findings in a previous candidate gene study.10 This evidence concerns the gene IL7R and myeloid sarcoma.