TGFB1 and hepatocellular carcinoma: In addition to the Ras/Raf/MEK/ERK and PI3K/AKT/mTOR signaling pathways, elevated TGF-β levels can also promote HCC development via a positive TGF-β/c-KIT feedback loop or TGF-β1/CD147 self-sustaining network [64, 65].