TNF and rheumatoid arthritis: This program includes patients enrolled in 2 multicenter precision‐medicine clinical studies collecting pretreatment synovial tissue at specific disease stages: untreated early RA (the Pathobiology of Early Arthritis Cohort [PEAC; http://www.peac-mrc.mds.qmul.ac.uk]) and established RA in patients with an inadequate response to tumor necrosis factor inhibitors (TNFi‐IR) (Response–Resistance to Rituximab versus Tocilizumab in RA [R4RA; http://www.r4ra-nihr.whri.qmul.ac.uk]).