The aggregation of α-synuclein increases upon conjugation with SUMO1 and α-synuclein PD mutants have increased tendency to be SUMOylated, triggering their prompt and robust aggregation (Rott et al., 2017), supporting the idea that SUMOylation may mediate the accumulation of toxic α-synuclein species. This evidence concerns the gene SUMO1 and Parkinson disease.