CD4 and rheumatoid arthritis: The percentages of CD3+, CD4+ and CD8+ T lymphocytes that expressed BTLA from RA patients were all higher than those of the controls (all p < 0.05), while the percentages of CD3+, CD4+ and CD8+ T lymphocytes that expressed HVEM and LIGHT were all lower than those of the controls (all p < 0.05).