Since complete inactivation of Ikbkap in mice isembryonic lethal, and FD carriers (heterozygous for the point mutation) expressing50% the levels of normal full length IKAP protein are asymptomatic, the generation ofa successful FD model likely requires that the level of normal IKAP protein bereduced between 0 and 50% the normal levels. This evidence concerns the gene ELP1 and Fabry disease.