ABL1 and Alzheimer disease: Cerebrospinal fluid data upon 6-month administration of nilotinib at its maximal daily tolerated dose during the clinical evaluation with AD patients indicated that this drug is only able to achieve CNS levels 10–20 times below its IC50 against c-Abl, pointing toward severe limitations for the use of FDA-approved c-Abl inhibitors to treat neurodegenerative disorders (Turner et al., 2020).