Fate-Mapping of GM-CSF Expression Identifies a Discrete Subset of Inflammation-Driving T Helper Cells Regulated by Cytokines IL-23 and IL-1β

？ FROG mice permit reporting and fate-mapping of GM-CSF-expressing cells ？ GM-CSF production by Th cells is vital for phagocyte invasion and tissue inflammation ？ The cytokines IL-23 and IL-1β are indispensable for GM-CSF expression ？ IFN-γ and IL-17A cannot maintain pathogenicity in the absence of GM-CSF in Th cell