Steel KJA, Srenathan U, Ridley M, et al. - Researchers sought to ascertain the immunophenotype, molecular profile, and function of synovial Tc17 cells in order to elucidate their role in PsA/SpA pathogenesis. In this study, cells were phenotypically, transcriptionally, and functionally examined by flow cytometry (n = 6–18), T cell receptor β (TCRβ) sequencing (n = 3), RNA-Seq (n = 3), quantitative reverse transcriptase-polymerase chain reaction (n = 4), and Luminex or enzyme-linked immunosorbent assay (n = 4–16). The outcomes distinguish synovial Tc17 cells as a polyclonal subset of Trm cells identified by polyfunctional, proinflammatory mediator production and CXCR6 expression. In PsA and possibly other types of SpA, the molecular signature and functional profiling of these cells may demonstrate how Tc17 cells can provide synovial inflammation and disease persistence.