CD274 and rheumatoid arthritis: TNF-primed knockout or mock-transfected RA- and NI-FLS were treated with soluble PD1, and transcriptomic responses were analysed by total mRNA sequencing.<h4>Results</h4>Analysis of publicly available RNA-sequencing datasets showed that, in early RA, PD-L1 and PD-L2 expression were significantly higher in lymphoid compared to myeloid and fibroid synovial tissue pathotypes.