A multidisciplinary team has illuminated the molecular mechanisms driving Parkinson’s disease pathology by investigating seeding-competent α-synuclein aggregates within human induced pluripotent stem cell (iPSC)-derived neurons lacking parkin function. Parkin, encoded by PARK2, is critical in familial PD and its dysfunction facilitates toxic α-synuclein accumulation, a hallmark of neurodegenerative synucleinopathies. Employing advanced protein aggregation assays and cellular models, the study reveals that parkin deficiency enhances the capacity of α-synuclein aggregates to seed further pathological misfolding intracellularly and propagate to neighboring cells via prion-like mechanisms. These findings advance understanding of PD etiology and potentially guide therapeutic strategies aimed at modulating parkin pathways or aggregate formation.