Strain specific CD40L expression analysis in heterozygous B-hCD40L mice by flow cytometry. thymocytes were collected from WT and heterozygous B-hCD40L (H/+) mice stimulated with PMA & Ionomycin and analyzed by flow cytometry with species-specific anti-CD40L antibody. Mouse CD40L was detectable in WT and heterozygous B-hCD40L mice. Human CD40L was exclusively detectable in heterozygous B-hCD40L but not WT mice.