However, further work is needed to test this hypothesis as it remains to be determined whether the shared K572Q mutation in the coding region of the Add3 gene in MNS and FHH rats relative to other strains (MHS, SHR, Dahl S rats) alters the function of this protein, its interactions with Add1, actin–spectrin interactions, and vascular tone. The gene discussed is ADD1; the disease is Melnick-Needles syndrome.