C2 and diabetic retinopathy: Notably, IER3 (p-value = 0.015), HLA-DQA2 (p-value = 1.06 × 10−11), C2 (p-value = 1.76 × 10−10), VARS2 (p-value = 0.005), VARS1 (p-value = 1.08 × 10−7), BAG6 (p-value = 6.20 × 10−13), TNXB (p-value = 3.17 × 10−10), AGER (p-value = 2.09 × 10−7), glutamate receptor 4 (p-value = 0.016), and MHC class I polypeptide-related sequence B (p-value = 1.02 × 10−8) demonstrated significant associations within the CMDKP, reinforcing their potential relevance in diabetic retinopathy.