The mouse NC14A domain (exons 17-18) was replaced with the human NC16A counterpart encoded by exons 18 and 19, which were flanked by loxP sites. A FRT-flanked neo cassette was removed via flp-mediated recombination. Cre-mediated recombination removed exons 18 and 19, maintaining the reading frame and resulting in an NC16A domain-truncated protein. (J:263966)