C4B and open-angle glaucoma: In African Americans with POAG, five complement proteins were significantly elevated in the AH samples compared to those with cataracts: C4A (FC = 2.33, p = 0.027), C4B (FC = 1.69, p = 0.015), complement component C7 (FC = 1.38, p = 0.025), F2 (FC = 1.31, p = 0.023), and C3 (FC = 1.21, p = 0.027).