CD4 and rheumatoid arthritis: Among immune cells, M2 macrophages, activated CD4 memory T cells, follicular helper T cells, and neutrophils were significantly correlated with EGFR expression levels; meanwhile, CD8 T cells were significantly associated with JUN expression levels, which suggested that EGFR and JUN might modulate RA synovial hyperplasia and progression by acting on these types of immune cells.