FOXP1 and neoplasm: In a second study investigating the role of IL-7 in Th9-mediated anti-tumor activity, the authors demonstrated that while Foxo1 and Foxp1 play opposite roles in the context of Th9 cell function in tumor regulation, Foxo1 indeed binds to the Il9 promoter and promotes Th9 cell differentiation and IL-9 production26.