In line with this view, it was suggested that, in inflammatory conditions (such as in the present case), the activation of DDAH may contribute to reduce the level of ADMA [32].There are also reports indicating that ADMA concentration is significantly lower (−48%) in the CSF of patients suffering of Alzheimer's disease or in pathological aging with cognitive impairment [33]. This evidence concerns the gene DDAH2 and early-onset autosomal dominant Alzheimer disease.