The targeting vector contains from 5' to 3' a loxP site, cDNA encoding the transmembrane and cytosolic domains of human SIGLEC16 gene, a human growth hormone polyadenylation sequence and an FRT-site flanked neo cassette inserted into exon 4. A second loxP site is inserted downstream of exon 5. Flp-mediated recombination removed the FRT-flanked neo cassette. Cre-mediated recombination removed exons 4-5. (J:274372)