HTR2C and Alzheimer disease: In this study, we assessed whether the levels of CSF AD biomarkers, scores on neuropsychological tests, and genetic biomarkers of AD (APOE haplotype) differed between patients with various 5HTR1B rs13212041, 5HTR2A rs6313 (T102C), 5HTR2C rs3813929 (−759C/T), and 5HTR6 rs1805054 (C267T) polymorphisms.