FLT1 and early-onset autosomal dominant Alzheimer disease: Cognitive and memory dysfunction in neurodegenerative diseases such as Alzheimer’s disease is postulated to be attributed to increasing titers of serum autoantibodies against 5-hydroxytryptamine receptors (5-HT2AR, 5-HT2CR, and 5-HT7R), vascular endothelial growth receptor 1 (VEGFR1), Stabilin-1 (Stab1), NMDAR, and endothelin type A receptors (ETAR).