NOS1 and hepatocellular carcinoma: In order to explore the potential mechanism by which miR-22-3p exerted its influences on metastasis and proliferation of HCC cells, bioinformatics tools (TargetScan, mirtarbase and microRNA.org) were employed to predict the downstream target candidate of miR-22-3p, and four mRNA candidate NOS1, AGPCR, BMPR1A and AKAP95 were obtained (Fig. 7A).