Further verification showed that the expression of FGF9 was decreased in renal tissues of DN patients (AUC = 0.902), and its recombinant protein could inhibit the expression of α-SMA and vimentin in high glucose-induced NRK-52E cells, indicating that activation of the circRNA/miRNA-FGF9 network promotes the EMT of renal tubular epithelial cells. The gene discussed is FGF9; the disease is liver dysplastic nodule.