Besides, whether TGFβ-induced factor homeobox 2 (TGIF2), a transcriptional repressor [17], could be one downstream functional gene of circ-RNF13/miR-424-5p axis was further confirmed, and the underlying mechanism on regulating malignant cell progression of HBV-expressing HCC cells and HBV infection was also explored. The gene discussed is RNF13; the disease is hepatocellular carcinoma.