This phenotype along with recent publications demonstrating bicuspid aortic valve and aortic valve stenosis in Gata5-null and Gata4;Gata5 compound heterozygote mice suggest that endocardial specific deficits of the G296S protein may contribute to the aortic and pulmonary valve stenosis [43], [44]. The gene discussed is GATA5; the disease is aortic valve stenosis.