YAP1 and hepatocellular carcinoma: Snail family transcriptional repressor 2 (Snail2) and yes-associated protein 1 (YAP1) are known oncogenes that are up-regulated in cancer (55, 56), circRNAPCNX serves as a sponge for miR-506 and inhibits the anti-cancer activity of miR-506 via the circRNAPCNX-miR-506-Snail2/YAP axis in HCC (57).