CD4 and Behcet disease: Intraperitoneal injection of butyrate to BD mice also increased the frequency of CD25+Foxp3+ cells (1.63 ± 0.57% vs. 1.09 ± 0.45%), and CD4+CD25+Foxp3+ cells (1.01 ± 0.32% vs. 0.29 ± 0.13%) compared to untreated BD mice (Figures 5K, L) but no statistically significant differences were observed.