Several loss-of-function mutations in the humanParkin RING-in-between-RING (RBR) E3 Ubiquitin Protein Ligase (PRKN) gene, which encodes Parkin, have been associated with the autosomal recessive juvenile form of Parkinson’s disease (PD), a devastating disease due to loss of dopaminergic neurons in the midbrain Substantia Nigra2. The gene discussed is UBE2E3; the disease is Parkinson disease.