REN and Renal insufficiency: Our study retrospectively analyzed the efficacy and safety of hydroxychloroquine and leflunomide in patients with IgAN with moderate proteinuria and mild to moderate renal insufficiency, and the results showed that both hydroxychloroquine combined with a renin-angiotensin system inhibitor, and leflunomide combined with a renin-angiotensin system inhibitor were more effective than a renin-angiotensin system inhibitor alone in improving proteinuria and stabilizing renal function in IgAN patients.