This is in agreement with previous studies showing that classification performance of this marker was better in subjects with clinical dementia than those in pro-dromal and pre-clinical stages and improved when combined with age, ApoE-ε4 carriership and GFAP.13 The observed amyloid-β-independent longitudinal decreases might indicate these decreases strongly depend on age, further complicating the clinical use of this biomarker for prognostic purposes. The gene discussed is APOE; the disease is dementia.