BTLA and systemic lupus erythematosus: There was also no significant difference in the expression of BTLA on stimulated Th17-cells in healthy controls as compared to SLE patients with lupus nephritis (40.2% ± 19.8% vs. 44.7% ± 32.2%, p = 0.93) and in comparison of healthy controls versus SLE patients without lupus nephritis, respectively (40.2% ± 19.8% vs. 22.6% ± 12.9%, p = 0.11).