An ERT2cre-encoding gene fused with a poly(A) signal and a neomycin-kanamycin resistance gene flanked with two FRT sites were inserted into the exon 2 of the S1pr2 gene, which encodes S1P2, on a BAC clone (RPCI23.C-168D6). Correctly targeted clones were injected into pronuclei of C57BL/6 zygotes to generate transgenic funder lines. The founder mice were identified by PCR and were further crossed with CAG-Flp transgenic mice to remove the neomycin-kanamycin resistance gene cassette. Line numbers were not indicated. The pound symbol (#) is used when no line is specified and/or lines are pooled.