STAT3 and cancer: Circ-BANP, which was abnormally highly expressed in hepatocellular carcinoma cells, could promote the expression level of target gene, TLR4, through sponge adsorption of miR-let-7f-5p, and further regulate the expression of VEGF-A and VEGF-2 through the STAT3 signaling pathway to affect the cancer angiogenesis [114].