The targeting vector replaced exon 4 and the 3UTR with a loxP site, exon 4, 3UTR, 3x SV40 poly(A) terminator, FRT-flanked neomycin cassette, loxP site, and exon 4 fused to AcGFP. The neomycin selection cassette was removed via flp-mediated recombination. (J:273745)