NOTCH3 gene mutation is associated with cerebral autosomal dominant arteriosis with subcortical infarction and leukoencephalopathy (CADASIL).[4]NOTCH3 gene is mainly expressed in smooth muscle cells of arterial vessels.[5]NOTCH3 protein belongs to NOTCH3 receptor family, which extracellular region contains 34 epidermal growth factor like (EGF-like) repeats. The gene discussed is NOTCH3; the disease is Leukoencephalopathy.