MTOR and hepatocellular carcinoma: In contrast to our data, one study that examined effects of dihydroxyacetone, a combustion production of propylene glycol and glycerol in e-cig vapor on human hepatocellular carcinoma cell line, showed slight increases in p-mTOR, while mTOR, RICTOR and RAPTOR displayed fluctuating levels (Hernandez et al., 2022); these differences could be due to the levels of dihydroxyacetone in an in vitro setting.