"Study showed that a genetic variant in the 5' UTR of DDX39B reduces translation of DDX39B mRNAs and increases multiple sclerosis (MS) risk. Importantly this DDX39B variant showed strong genetic & functional epistasis with allelic variants in IL7R exon 6; study establishes the occurrence of biological epistasis in humans & provides mechanistic insight into the regulation of IL7R exon 6 splicing & its impact on MS risk."xsd:string