APOE and amyloidosis: Considering that APOE4 brings the start of amyloid pathology earlier, our findings suggest that the increased focal uptake in the G(−)F(+) group might be mainly driven by combination of older age and APOE4. Alternatively, as current Aβ PET ligands are limited in detecting the early state of Aβ accumulation, including diffuse plaques and sparse-to-moderate degrees of neuritic plaques (Jack et al., 2013), amyloid accumulation may appear in focal form amyloid PET testing, though amyloid deposition is actually positive.