To investigate whether pathways of bile acid synthesis were altered in AD animals, the levels of cholesterol and bile acid intermediates including 27-hydroxycholesterol, 25-hydroxycholesterol, 7-α-hydroxycholesterol cholest5-en3β,7α-diol, 3β-hydroxy-5-cholestenoic acid, and 3β,7α-dihydroxy-5-cholestenoic acid were quantified by ultra-performance liquid chromatography-tandem mass spectrometry in WT, APP/PS1, and AppNL-G-F female and male mice. The gene discussed is APP; the disease is Alzheimer disease.