Serum PCSK9 was significantly higher in subjects with diabetic kidney disease (p = 0.020; Fig. 2A) and in patients with a history of MACE (p = 0.043; Fig. 2B), whereas atherosclerotic vascular disease, nephropathy, and neuropathy did not affect PCSK9 levels (Additional file 1: Table S2). The gene discussed is PCSK9; the disease is diabetic kidney disease.