A loxP site was inserted upstream of exon 3. An FRT-flanked neomycin resistance cassette with a 3' loxP site was inserted downstream of exon 3. Flp- and cre-mediated recombination removed the neo cassette and exon 3, respectively. The absence of transcript expression was confirmed by qRT-PCR on white adipose tissue, brown adipose tissue, bone marrow, liver, kidney, and skeletal muscle extracts. (J:173404)