CASC3 and Crouzon syndrome-acanthosis nigricans syndrome: BTZ, which is a proteasome inhibitor that was approved for treatment of multiple myeloma, was demonstrated in animal studies to kill short-lived and long-lived plasma cells [9], which is the main antibody-producing cell type, and was found to reduce autoantibodies in several autoimmune conditions, including myasthenia gravis, systemic lupus erythematosus (SLE), chronic allograft nephropathy, and antibody-mediated kidney transplant rejection [10–13].