APP and Alzheimer disease: Several on-chips studies have been conducted using human neural progenitor cells transduced with familial AD-specific mutated genes, such as FAD 670N/M671L/V717, APP, and PSEN1. In AD pathogenesis, astrocytes play an essential role in the progression of AD, with “a double-edged sword” effect on neuroinflammation, owing to their neuroprotective and neurotoxic effects138,480,481.