Studies on another transgenic mouse model of PD by Jiang and colleagues (2021) [70] have established a link between hyperphosphorylation of the amyloid precursor protein APP and impaired hippocampal neurogenesis, characterized by reduced NSC numbers, neural proliferation and differentiation; the model expresses a mutated form of the vacuolar protein sorting protein 35 (VPS35) that is associated with late-onset autosomal dominant PD. Here, APP is linked to Parkinson disease.