Notably, we developed an acid inflammatory‐sensitive PEG‐Linker that can cross‐link IL‐3 to create IL‐3 nanogels (IL3 NGs) and precisely deliver IL‐3 with RVG29, a 29‐residue peptide derived from the rabies virus glycoprotein (RVG), (hereafter referred to as RVG‐IL3 NGs) for PD therapy (Scheme1A). This evidence concerns the gene IL3 and Parkinson disease.