APC and Familial adenomatous polyposis: The first GEXM was established to phenocopy Familial Adenomatous Polyposis (FAP) by TALEN-mediated targeting of the apc gene in Xenopus tropicalis, replicating the human frame-shifting mutations and complementing models such as the Apcmin mouse and ENU-induced apc zebrafish mutant (Van Nieuwenhuysen et al., 2015).