Those with intense C3 staining had more frequently mesangial hypercellularity (81.8% vs. 64.3%, p = 0.008), segmental sclerosis (64.5% vs. 51.4%, p = 0.08) and a greater prevalence of global glomerulosclerosis (median percentage of glomeruli with global sclerosis, 20.7% vs. 16.6%, p = 0.11), compared to those without intense C3 staining. The gene discussed is C3; the disease is glomerulosclerosis.