MTOR and metabolic dysfunction-associated steatotic liver disease: Furthermore, the upstream regulator mTOR (mammalian target of rapamycin) was suggested to be inhibited in the LBW w/NAFLD subjects compared with the NBW controls, whereas mitochondrial UCP2 (uncoupling protein 2) appeared to be inhibited among the LBW subjects both w/NAFLD and w/o NAFLD, compared with the NBW controls (Table S4).