Indeed, we learned from previous attempts to model FD in animals that a very narrow window of IKBKAP expression at specific locations during development separates a viable model with symptoms close to FD patients from embryonic lethality (Abashidze et al., 2014; Chen et al., 2009; Creppe et al., 2009; Dietrich et al., 2012, , 2011; George et al., 2013; Hunnicutt et al., 2012; Jackson et al., 2014; Morini et al., 2016). This evidence concerns the gene ELP1 and Fabry disease.