NOTCH2 and coronary artery disorder: At earlier developmental stages (E9.5 and E10.5), Hes1 mutant mice embryos showed defects in the proliferation of SHF, a reduction in the number of NCCs and failure to completely extend the outflow tract.28 The down‐regulated expression of NOTCH2 in the CHD group may provide insight into the pathogenic mechanism of CHD.