PABPC1 and hepatocellular carcinoma: To examine the biological consequences of AR/ADAR1 expression in HCC development, we focused on 5 circRNAs that originated from PABPC1 (polyadenylate-binding protein 1) gene that were all upregulated more than five-fold after knocking down AR (Figure 6a), whereas AR did not regulate PABPC1 transcript level (Supplementary Figure S4a).