In summary, the present systematic review and meta-analysis indicate, as key players of fibrosis in DN, sixteen genes (ACE, AGT, EDN1, EPO, FLT4, GREM1, IL1B, IL6, IL10, IL12RB1, NOS3, TGFB1, IGF2/INS/TH cluster, and VEGFA). The gene discussed is ACE; the disease is liver dysplastic nodule.