RPTOR and Hepatic steatosis: On the contrary, other studies demonstrated that activating mTORC1 with the deletion of tuberous sclerosis 1/2 (TSC 1/2) complex, which is a negative regulator of mTORC1, protected mice from liver steatosis [57], while other groups observed increased steatosis and liver injury in mice deficient for Raptor in the liver [58].