MTOR and colorectal carcinoma: For example, leptin might regulate the proliferation, apoptosis, or invasion of CRC cells through the PI3K/Akt/mammalian target of rapamycin (mTOR) [232,233], nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent Silent Information Regulator 2 Homolog 1 (SIRT1) [234], ERK1/2 [235,236,237], MAPK [236,237,238], JAK2, STAT3, activator protein 1 (AP-1) [239,240] and NF-κB [241] signaling pathways.