IL15 and rheumatoid arthritis: Numerous reports have established a connection between elevated levels of inflammatory cytokines and immune-mediated diseases, such as IL-1RA, IL-6, and IL-18 in COVID-19 patients [23]; TNF-α, IL-1, IL-6, IL-15, and IL-17 A in rheumatoid arthritis (RA) [24, 25]; TNF, IFN-γ, and IL-6 in systemic lupus erythematosus (SLE) [26]; and IL-4, IL-5 and IL-13 in the pathogenesis of asthma and other TH2 cell/IgE-mediated immune diseases [27].