Three potential mechanisms for how BCAAs lead to the occurrence of T2DM are: First, increased levels of BCAAs can result in the accumulation of toxic metabolites, which in turn causes mitochondrial dysfunction and a decrease in secretion of insulin in pancreatic beta cells (18, 19); second, perturbations of BCAAs can induce insulin resistance through the mTOR signaling pathway (20); third, increased levels of BCAAs can activate the rapamycin pathway, which then disturb the action of insulin and promote the degradation of insulin receptor substrates (21, 22). The gene discussed is INSR; the disease is type 2 diabetes mellitus.