To further confirm the role of miR-21-5p/SMAD7 in keloid, miR-21-5p inhibitor and SMAD7 low expression plasmid were co-transfected into keloid fibroblasts, and the transfection efficiency was verified by qRT-PCR (P < 0.05, Figure 3(g)). The gene discussed is SMAD7; the disease is keloid.