A loxP site was inserted upstream of exon 3 and a downstream floxed neo cassettes was inserted downstream of exon 3. Chimeric progeny were bred with a cre deleter strain to remove exon 3, leaving behind a single loxP site. Gene inactivation was confirmed by Southern blotting of cDNA derived from tail mRNA. Expression levels of Clec2g and Clec2i genes were unaffected in these mice.