MTOR and obesity due to melanocortin 4 receptor deficiency: One of the major IL-6-driven signaling pathways in obesity and HCC development is mechanistic target of rapamycin (mTOR)7, which is a key signal transducer in the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/Protein Kinase B (AKT) pathway.