MTOR and hepatocellular carcinoma: Transcription factors (TF) such as Spalt-like protein 4 (SALL4) and signaling pathways such as Ras/Raf/Mitogen-activated protein kinase/ERK kinase (MEK)/extracellular-signal-regulated kinase (ERK) pathway, phosphatidylinositol-3-kinase (PI3K)/Akt/mechanistic target of rapamycin (mTOR) pathway, Wnt/β-catenin pathway, and Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway have been identified as key players in HCC (7).