Snapshot of coordinated interplay between T cell differentiation and principle metabolic pathways monitoring different CD4 helper T cells. A naive CD4 T cell differentiates into different helper T cell subsets programmed by a master transcriptional regulator and predominant metabolic signaling molecule and pathway. Mammalian target of rapamycin complex 1 (mTORC1) is essential for Th1, mTORC2 for Th2, mTORC1 and HIF-1α for Th17, and AMP-activated protein kinase (AMPK) for Treg differentiation. Despite the different molecular metabolic regulators, Th1, Th2, and Th17 adopt aerobic glycolysis as their principle pathway, and on the other hand, Tregs adopt lipid oxidation.