The authors demonstrated that a significant proportion of synovial T-cell subsets were triple-positive for GM-CSF, TNF, and IL-17 or IFN-γ compared with matched blood subsets and that these polyfunctional T cells were positively correlated with disease activity (measured with the Disease Activity in PSoriatic Arthritis (DAPSA) score), while single cytokine-producing T cells were not. The gene discussed is IL17A; the disease is arthritic joint disease.