IL6ST and myeloid sarcoma: In light of these current observations, and considering serum sgp130 appears to be a polygenic trait influenced by genomic variants acting in trans (60), decreased circulating sgp130 levels constitute likely a secondary effect of the major causative link to MS risk conferred by rs7731626, which thus far is understood as upregulation of both ANKRD55 and IL6ST expression in CD4+ T lymphocytes (34, 36).