IL6 and rheumatoid arthritis: The immunohistochemistry (IHC) and Immunofluorescence (IF) results showed elevated levels of the proinflammatory cytokines IL-1β, IL-6 and TNF in RA synovial tissue (Supplementary Fig. 2e–, h), while FISH indicated increased piENOX2 expression in RA synovial tissue (Fig. 2a, b).