MASP2 and rheumatoid arthritis: Deficiency or blockade of MASP-2 in experimental models has been shown to have beneficial effects in ischemic reperfusion injury (21, 37–39), transplantation (39), rheumatoid arthritis (51), TMA (52), pneumococcal meningitis (53), SARS-Cov-2 infection (54), sickle cell disease (55), and renal fibrosis (40).