With increasing availability of hiPSC lines generated from fibroblasts of patients suffering from neurodegenerative disorders and carrying disease-associated mutations (e.g. in genes including PSEN1 and APOE E4 in AD [74, 75], C9orf72 and SOD1 in ALS [76], LRRK2 and SNCA in PD [77]) and constantly improving hiPSC differentiation protocols [78–83], in vitro BBB models may become a useful tool to study FUS-mediated drug transport. The gene discussed is PSEN1; the disease is Alzheimer disease.