GFAP and Alzheimer disease: On the contrary, CSF GFAP presented the lowest concentration in the MCI group (median 8,946.2 pg/ml, IQR 7,028.8, 13,842.7), followed by HC (median 11,145.3 pg/ml, IQR 6,980.5, 14,373.8) and AD (median 13,663.5 pg/ml, IQR 9,945.4, 21,059.1).