NOS3 and migraine disorder: The increased susceptibility to migraine is supported by genetic polymorphisms, such as encoding endothelin type A receptor (EDNRA), encoding MTHFR, encoding endothelial nitric oxide synthase (NOS3), encoding ACE, encoding β-2 transforming growth factor (TGFB2), encoding β-2 transforming growth factor receptor (TGFBR2) and neurogenic locus notch homolog protein 3 (NOTCH3) (a receptor that is involved in vascular development and integrity) [12].