circRNAs are also implicated in DN: dozens of circRNAs show altered expression in diabetic kidneys, functioning as miRNA “sponges.” For instance, circEIF4G2 is significantly upregulated in tubuloepithelial cells under high glucose and aggravates renal fibrosis by sequestering miR-218, leading to increased SERBP1 and downstream TGF-β1/Collagen I production [67]. Here, TGFB1 is linked to renal fibrosis.