CYP19A1 and Alzheimer disease: Further support of the role of aromatase in human cognition comes from postmortem studies in humans, which demonstrate region-specific changes in aromatase levels in Alzheimer’s disease (Ishunina et al., 2005; Prange-Kiel et al., 2016), suggesting that aromatase may be implicated in normal as well as pathological variations in learning and memory.