Astrocytes derived from induced pluripotent stem cells in patients with LRRK2 PD express increased alpha-synuclein, resulting in altered calcium homeostasis and increased cytokine release upon inflammatory stimulation131 and display altered morphology of extracellular vesicles and altered morphology and distribution of multi-vesicular bodies, with overaccumulation of phosphorylated alpha-synuclein and reduced trophic support and viability of dopamine neurons132. The gene discussed is SNCA; the disease is Parkinson disease.