CTLA4 and myocarditis: Alemtuzumab (anti-CD52 mAb) and abatacept, a protein consisting of the human CTLA-4 extracellular domain fused to the Fc portion of IgG, acting as a CTLA-4 agonist, have been employed for the treatment of single cases of glucocorticoid-refractory myocarditis (198, 250).