IL3 and Alzheimer disease: Considering 2 μg of IL‐3 may induce a pro‐inflammatory response and more severe microglial activation (Figure 2D,G), we thus chose 1 μg of IL‐3 to treat the mice, which was consistent with the administration dosage in a recently reported AD mouse model.[8] Following the administration of mouse free IL‐3, the total distance traveled and movement speed of AAV‐hα‐Syn mice in the open field as well as their performance in pole‐climbing and grasping tests were significantly improved (Figure3A–F).