TM2D1 and Alzheimer disease: Considering the phenotypic similarities of amrt and bisc to amx in Drosophila embryonic neurogenesis, the similarities between TM2D1-3 in human cells in the context of phagocytosis, and the similarities of Tm2d1-3 knockout mice in the context of embryogenesis, we propose that studies of rare genetic variants, epigenetic regulators or proteomic changes in other TM2D genes may reveal novel risk factors or biomarkers in epidemiologic study of AD and other forms of dementia.