1X10^6 mouse splenocytes were surface stained with PE-Anti-Mouse CD4 (PE-65104, Clone: GK1.5), CoraLite®488-Conjugated Anti-Mouse CD25 (CL488-65137, Clone: PC61.5) and 0.06 ug APC-Anti-Mouse CD357 (GITR) (APC-65102, Clone: DTA-1). Cells were not fixed. CD4+ lymphocytes were gated for analysis of CD25 and CD357 (GITR) staining.