The transgene consists of a modified cre recombinase gene fused to exon 1 of a human CD2 minigene just upstream of the translation initiation codon. The human CD2 promoter was used to drive transgene expression in T lymphocytes. The cre recombinase sequence was modified to include a nuclear localization signal and a modified KOZAK consensus sequence. Transgene expression was confirmed by immunohistochemical analysis of thymus and spleen from transgenic animals. (J:81648)