Taken together, these findings suggest that mTOR/lipin1 signaling may be a critical downstream pathway of βAR participating in the regulation of WAT browning, showing novel roles for mTOR and lipin1 in the regulation of energy metabolism; β3-activated mTOR-lipin1 axis may critically underlie the molecular basis of PKA-regulated WAT browning, providing adipose target candidates for the development of drugs to treat obesity (Figure 9). This evidence concerns the gene MTOR and obesity due to melanocortin 4 receptor deficiency.