Measurement of soluble and insoluble Aβ levels by using enzyme-linked immunosorbent assay (ELISA) showed that soluble Aβ42/Aβ1-42 species, which are synaptotoxic in AD,56 were significantly increased in both the hippocampus and cortex tissues of APP/PS1ΔE9 mice with overexpression of ACAA1 p.N299S relative to the ACAA1 WT group (Fig. 4b). This evidence concerns the gene ACAA1 and Alzheimer disease.