(Gln22,Asn23)-Amyloid _-Protein (1-40) is a transgenic mice expressing vasculotropic Dutch/Iowa (E693Q/D694N) mutant human brain A_ precursor protein (TG-SWDI), which accumulates abundant cerebral microvascular fibrillar amyloid deposition and exhibits strong neuroinflammation. In vitro, double-mutated A_ peptides showed a tendency to increase fibrillation and pathogenicity compared with Dutch and Iowa single mutants.