STAT3 and myeloid sarcoma: In addition, one allele of the IL-10Rα S138G polymorphism, which encodes for a loss-of-function allele for IL-10-induced STAT1 and STAT3 activation (78) is associated with MS disease susceptibility and severity in Tunisians (79), and two mutant alleles confers an increased risk for MS specifically in men who are normally less susceptible than women in developing relapsing-remitting MS (79).