CXCR1 and rheumatoid arthritis: Intriguingly, the inflammatory fibroblast subset in RDEB mice shared important features, i.e., expression of PDPN, CC, and CXC chemokines and cytokines, with the synovial fibroblast subset found in patients with rheumatoid arthritis (73) or the ileum fibroblast subset found in patients with inflammatory bowel disease (74).