A side-effect of certain types of CAR-T therapies is the development of idiopathic parkinsonian symptoms, such as tremors and ataxia. However, the cause of these symptoms remains unknown. One potential explanation is that certain rare brain cell subtypes in the putamen and caudate nucleus express receptions which are attacked by the CAR-T cells. Through scRNA-Seq analysis, this project will determine which (if any) brain cell subtypes express these receptors and explore alternative hypotheses that can explain these symptoms.