Finally, our group has re-examined publicly available single cell transcriptomic data from synovial biopsies from individuals with RA.19, 21 This analysis demonstrated that fibroblasts in the sub-lining layer of the synovium are particularly enriched for both known and putative pro-algesic mediators such as nerve growth factor (NGF),22 IL-6,23 complement C3,24 leukaemia inhibitory factor (LIF)25 and IL-11.26 This evidence concerns the gene NGF and rheumatoid arthritis.