Like the potential involvement of eNOS and VEGF in AD pathology and maintenance of collaterals in the results that we obtained in eNOSTg; CX3CR1−/− mice, interactions between fractalkine and VEGF may also be involved in the inhibition of rarefaction in the CX3CR1−/−; 2xTg mice. The gene discussed is VEGFA; the disease is Alzheimer disease.