IL6 and Castleman disease: The interleukin-6 (IL-6) inhibitors, one of which is tocilizumab, a monoclonal autoantibody, has been studied and approved for rheumatoid arthritis treatment back in 2010 along with other autoimmune diseases including systemic-onset juvenile idiopathic arthritis, Castleman's disease, multiple myeloma, systemic lupus erythematosus, and, lately, giant cell arteritis in 2017.