PRKAA2 and hepatocellular carcinoma: We used the Pa2-491 peptide to treat hepatoma HepG2 cells with activated cAMP-PKA signaling and found that Pa2-491 treatment significantly blocked phosphorylation of AMPKα2 at S491 and α1 at S496, along with increased AMPKαT172 phosphorylation (Fig. 5A).