These universal fibroblasts also expressed high amounts of dermatopontin (DPT) and genetically engineered mice which express the fluorescently labelled DPT protein confirmed their transcriptional trajectory giving rise to three specialized fibroblast subsets demarked by genes Cxcl5, Adamdec and Lrrc15. In RA synovial tissue, Pi16+ fibroblasts were shown to give rise to Cxcl5+ fibroblasts which expressed high levels of proinflammatory cytokines IL-6 ad IL-1β and chemokines CCL2 and CCL7 thought to be located in the sub-lining. This evidence concerns the gene IL1B and rheumatoid arthritis.