T2DM patients with DR had lower serum and aqueous humor myonectin concentrations compared with those without DR [serum myonectin: 244.1 (199.96–282.85) ng/mL vs. 307.36 (237.2–344.58) ng/mL, P < 0.001; aqueous humor myonectin: 118.74 (102.71–138.91) ng/mL vs. 159.12 (131.44–183.02) ng/mL, P < 0.001]. The gene discussed is ERFE; the disease is type 2 diabetes mellitus.