OPN3 and hepatocellular carcinoma: Although no direct links between OPN3 and 5FU treatment have been identified in normal cells, in hepatocellular carcinoma cells, OPN3 is involved in regulating 5FU-induced apoptosis via control of the phospho-Akt/total Akt and Bcl2/Bax ratios (Jiao et al., 2012).