Leucine‐rich repeat kinase‐2 (LRRK2) Gly2019Ser promotes endoplasmic reticulum (ER) stress and neural death in Parkinson's disease (PD) by interacting with thrombospondin‐1/transforming growth factor beta1 (THBS1/TGF‐β1) in dopamine neurons and mice. Here, LRRK2 is linked to Parkinson disease.