The targeting vector contains a human CD68 promoter (consisting of CD68 5'; flanking sequence with the 83 bp first intron [IVS-1] of the CD68 gene), a Cre recombinase/ERT2 fusion, an IRES, and polyA sequence. The vector is flanked by PhiC31 attP sites and contains a promoterless neomycin cassette upstream of the CD68 promoter. (J:335680)