IL17A and type 1 diabetes mellitus: The BHLHE40-driven triple-positive phenotype (IFN-γ+IL-17A+GM-CSF+) in T1D and the IL-1β-driven transdifferentiation from Th17 to GM-CSF+ Th in IBD further suggest the strong impact of disease microenvironments on differentiation pathways 30, 33.