GM-CSF-producing helper T cells have previously been identified to serve a nonredundant function in the initiation of autoimmune inflammation.An article by Sheng et al.recently published by Cell Research now suggests that the differentiation program of GM-CSF-producing cells from na(i)ve CD4+ T cells is distinct from that of Th1 and Th17 cells,and is regulated by the IL-7-STAT5 axis.