CDK5 and Alzheimer disease: Apart from these genes, APOE, CDK5, LMO4, PTEN, TGFβ 1 etc., were found to increase the abnormal protein aggregation and other characteristic features of Alzheimer’s disease (Brains of individuals with AD manifest two characteristic lesions: extracellular amyloid plaques and intracellular neurofibrillary tangles of hyperphosphorylated tau protein.