These changes are reminiscent of those seen in Lrrk2 mutant mice (10, –12, 14) and provide a plausible explanation for how Gba1 mutations may increase PD risk in a manner similar to that seen upon LRRK2 mutation (10): Vulnerable neurons fail to receive adequate neuroprotection from cholinergic interneurons and present with a disease of aging. The gene discussed is LRRK2; the disease is Parkinson disease.