IL3 and Parkinson disease: In this study, it is found that astrocytic IL‐3 and microglial IL‐3R are positively responsive to α‐synuclein pathology in the brains of transgenic A53T Parkinson's disease (PD) mice and in an adeno‐associated virus (AAV)‐human α‐synuclein (AAV‐hα‐Syn)‐injected PD mouse model.