CXCL1 and arthritic joint disease: Rossana Domenis et al. found that synovial fluid-derived exosomes from arthritis patients significantly stimulated M1 macrophages to release inflammatory cytokines IL-1β, chemokines chemokine (C-C motif) ligand 20 (CCL20), CCL15 and C-X-C motif chemokine ligand 1 (CXCL1), and MMP12 and MMP7, which can promote the inflammatory infiltration of chondrocytes and the destruction of cartilage extracellular matrix [11].