MTOR and hepatocellular carcinoma: Similarly, GDF11 also activated non-Smad (e.g., AMPK, MAPK, mTOR, PI3K) pathways in a wide range of cell types, such as cardiomyocytes, neural stem cells, human hepatocellular carcinoma cells, primary hepatocytes, and mesenchymal stem cells [14,30,31,32,33].