Also, in the human hippocampus, the levels of endogenous α-synuclein are increased in Lewy Body Dementia (LBD) and the numbers of (SRY-sex determining region Y)-Box Transcription Factor 2) (SOX2)-positive cells are decreased [396], a phenomenon that triggers neurodegeneration and impaired neurogenesis in the adult mouse brain [397]. The gene discussed is SNCA; the disease is Lewy body dementia.