As stated above, a growing body of research has revealed that there is abnormal brain cholesterol metabolism in the brain in aging human and animals, SAMP8 mice, diabetic mice, FAD (5xFAD and APP/PS-1) animals, AD patients, genetic forms of AD animals and patients (ApoE4 allele, mutation of NPC1 or NPC2, polymorphism or mutations of ABC transporter and LDL receptor family). This evidence concerns the gene NPC2 and Alzheimer disease.