CCL20 and rheumatoid arthritis: CCL20 mediates its effect by binding to the CCR6, which is mainly expressed by T helper 17 (Th17) cells; cells that not only fulfill a crucial role in protecting the host against fungal and bacterial infections but also in multiple immune‐mediated inflammatory disorders, comprising RA, inflammatory bowel disease, uveitis, multiple sclerosis, asthma, and psoriasis.11, 12, 13