IL3 and Parkinson disease: We found high levels of IL‐3 surrounded tyrosine hydroxylase (TH)‐positive DA neurons in the SNpc of A53T PD mice and the AAV‐hα‐Syn‐injected PD mouse model (Figure 1G,H), which further verified that IL‐3 signaling was closely correlated with nigrostriatal α‐synuclein pathology.