ADORA3 and hepatocellular carcinoma: Specifically, as for the anti-tumoral effect, the main receptor subtype involved results the A3AR for which the successful data obtained in preclinical studies lead to the development of A3AR selective agonists, now under evaluation in clinical studies for the treatment of hepatocellular carcinoma (Stemmer et al., 2013; Jacobson et al., 2017).