NGF and frontotemporal dementia: We have computed the Spearman index in order to evaluate the correlation between proNGF or NGF and the clinically validated biomarkers, as well as the other clinical variables [age, disease duration (in months), years education, time shift (time in months from the first and second symptom), presence of extrapyramidal or motor neuron disease (MND) symptoms, clinical dementia rating (CDR) global score, CDR sum of boxes, FTD-CDR score].