In recent years, various studies have explored the C3 deposition in glomerular capillaries and arterioles in association with IgAN and have revealed that peritubular capillary C3 deposition may be used as a predictor of a poor prognosis, while C3 deposition in the renal arterioles may be considered a marker of atherosclerosis [20, 22]. The gene discussed is C3; the disease is atherosclerosis.