Increasing concentrations of HVEM(23–39) or HVEM(31–39) modified peptides, where one or both cysteines were substituted, were tested in ELISA and compared to corresponding wild-type and scrambled (Ctrl peptide) peptides (at least two experiments in triplicate). The percentage of inhibition of the BTLA/HVEM binding was calculated in relation to the negative control (PBS). Statistical analysis was performed by comparing each concentration of each peptide to the same concentration of wild-type peptide HVEM(23–39). **: p< 0.01 following non-parametric One-way ANOVA and Dunn’s post-test.