In addition, due to the topographical rostral progression of HPτ pathology from the entorhinal/limbic regions to the neocortex, the frontal region is affected in the rather late stages of AD progression, and therefore, in early stages of the disease the frontal white matter, theoretically is less likely to develop degenerative axonal loss compared to the posterior white matter. The gene discussed is MRS2; the disease is Alzheimer disease.