CCL20 and rheumatoid arthritis: Analysis confirms that the IL-1B+CCL20+ macrophage cluster is enriched in patients with RA and positively correlates with RA disease activity (r = 0.44, P = 2.2 × 10−5) and change in DAS28CRP between baseline and 6 months following methotrexate-based therapy (r = 0.25, P = 0.019) (Fig. 5I).