An FRT-flanked selection vector containing a neomycin resistance gene and a single 5' loxP site was inserted upstream of exon 2 of the Mgl2 gene and a second loxP site was inserted downstream of exon 10 of the Clec10a gene. The selection cassette was subsequently removed from properly targeted mice by crossing to transgenic mice carrying Tg(ACTFLPe)9205Dym. (J:94077)