The main effects of IL-6 are Induction of differentiation of B cells into plasma cells and differentiation of myeloid stem cells Induction of acute phase reactants Enhancement of T-cell proliferation Induction of Tc-cell differentiation Pyrogenic activity Clinical relevance of IL-6 includes For anti-IL-6 mAb, treatment of multicentric Castleman disease in patients who are negative for HIV and human herpesvirus 8 (HHV-8), For anti-IL-6 receptor mAb, treatment of rheumatoid arthritis when the response to TNF-antagonists is inadequate and treatment of juvenile idiopathic arthritis, giant cell arteritis, and of severe cytokine release syndrome following CAR (chimeric antigen receptor) T cell treatment. In combination with dexamethasone, treatment of patients with COVID-19 with hypoxia and systemic inflammation.