The first loxP was inserted into intron 14, and the second loxP together with neomycin-resistant gene flanked by FRT sites was inserted into intron 16. The Neo-cassette was removed using FLPeR mice, leaving exons 15 and 16 floxed. The 2 exons encode part of Tie1 intracellular domain (ICD). (J:271100)