GLS and Cowden disease: Glutamine has been reported to enhance mTORC1 signalling, which supports the differentiation of naïve cells into Th1 cells and inhibits Treg‐cell differentiation.37 In addition, Michihito Kono et al reported that the inhibition of Gls1 reduced p70 S6K phosphorylation, Th17 differentiation and the severity of EAE.20 Consistent with these studies, our findings confirmed that Gls1 regulates different T‐cell subset responses by activating mTORC1 signalling in a mouse CD model.