IL6 and graft versus host disease: Enhanced Treg production following IUT, particularly of CD62L+ CD25+ FOXP3+ Tregs, protects against graft-v-host disease [55, 56], and together with putative Breg (expressing IL10, IL5, IL6, FOXP3, TGF-β), probably influenced the resulting tolerogenic or immunogenic responses [37, 38].