APOE and cerebritis: However, while other groups using mass spectrometry-based techniques for quantifying plasma amyloid-β to predict cerebral amyloid status (Ovod et al., 2017; Nakamura et al., 2018; Schindler et al., 2019) commonly included age and APOE ε4 carrier status in predictive models, we found that including these variables made no material difference to the ability to predict amyloid status when using LC-MS amyloid-β1-42/amyloid-β1-40, and only small improvements using the LC-MS composite proposed by Nakamura et al. (2018).