MYOM2 and rheumatic heart disease: Monoclonal antibodies derived from RF/RHD patients have provided evidence for cross-reactive autoantibodies that target GAS epitopes such as group A carbohydrate, N-acetyl-beta-d-glucosamine (GlcNAc), and M protein with host proteins including heart valve endothelium, laminin, and laminar basement membrane and cardiac myosin [Reviewed in Ref.