High peak aortic blood velocity in adult heterozygous Klf3 point mutants (Klf3H275R/+) was caused by aortic valvular stenosis as shown by augmented valvular gradients in blood velocity (Figure 2A) and blood pressure in Klf3H275R/+ mice (Figure 2B,C), and by abnormal valve morphology detected by gross dissection (not shown), histopathology (Figure 3A), and scanning electron microscopy (Figure 3B). The gene discussed is KLF3; the disease is aortic valve stenosis.