SLAMF1 and rheumatoid arthritis: Compared to peripheral blood T cells from the same patient or healthy volunteers, SLAMF1 expression levels in synovial fluid and synovial tissue T cells of RA patients were significantly upregulated.In the CIA mouse model, immunohistochemical staining of joint tissue showed significant high expression of SLAMF1 in diseased joints.SLAMF1 was present in CTL, Th cells, NK cells, NKT cells, etc. derived from CIA mice. Therefore, SLAMF1 may affect the pathogenesis of RA by participating in the inflammatory response mediated by these infiltrating immune cells.