IL6R and Castleman disease: Alternatives to IL-6R blockade and corticosteroids are currently being studied for their use in the management of CRS and ICANS, including siltuximab, an anti-IL-6 monoclonal antibody that is used clinically for Castleman’s disease, and anakinra, a recombinant IL-1RA protein used clinically for rheumatoid arthritis and that can block IL-1, a cytokine that has been implicated in CRS and ICANS pathogenesis (22, 31, 32).