BTLA and systemic lupus erythematosus: Furthermore, there were significant different percentages of BTLA expression on stimulated Th2-cells between active and inactive SLE patients (CD3+CD8−CD69+IL-10+: %BTLA, 80.5% ± 18.0% vs. 54.4% ± 24.3%, p = 0.025, Figure 3D).