This single-copy, targeted insertion into the Hprt locus consists of the macrophage-specific mouse Cd68 promoter followed by a cDNA encoding the human B cell leukemia/lymphoma 2 protein and the mouse EF1 polyadenylation signal; the vector also contains sequence that repairs an inactivating deletion in the Hprt gene of the ES cell line. Human BCL2 mRNA and protein are detected by reverse transcriptase/polymerase chain reaction (RT-PCR) and flow cytometry, respectively, of thioglycollate-elicited peritoneal macrophages from transgenic mice. (J:166498)