CD19 and rheumatoid arthritis: Research by Anang DC et al. revealed a notable phenomenon: compared to lymphoid tissues from healthy individuals, the number of CD19 + B cells, CD4 + CXCR5 + follicular helper T cells, and CD8 + CXCR5 + follicular T cells is significantly increased in the lymphoid tissues of patients with rheumatoid arthritis (RA) and individuals at risk for RA [28].