CHD8 and Neurodevelopmental delay: Our findings of effects in Chd8+/flox mice due to ablation in excitatory neurons are consistent with effects reported in earlier in vitro studies of both heterozygous and homozygous neuronal ablation40,69, and extend previous studies of adult homozygous mutant Chd8−/− conditional mutant mice that did not examine NDD-relevant heterozygous mutants44.