P2RX7 and hepatocellular carcinoma: To determine if dysregulation of P2 purinergic receptor expression is associated with hepatocyte transformation to HCC phenotype and to identify a suitable in vitro model system for mechanistic studies, we analyzed P2 purinergic receptor mRNA expression by qRT-PCR in four human hepatocellular carcinoma cell lines - Huh7, Hep3B, SNU-387, PLC/PRF/5, and normal human primary hepatocytes.