Recently, Wang et al. [30] demonstrated that the IL-6-inducible proto-oncogene protein intestine-specific homeobox (ISX) gene induces IDO1 and TDO expression, which increases Kyn and AhR and thereby promotes the tumorigenic potential and immunosuppression of hepatocellular carcinoma cells expressing CD86 and PD-L1. This evidence concerns the gene ISX and hepatocellular carcinoma.