GBA1 and Parkinson disease: The greater accumulation of oligomeric peptides (presumably α‐synuclein) in severe GBA1 mutant lines might explain the clinical facts that severe GBA1 mutations are associated with a higher risk of PD, earlier age of onset, and faster disease progression (Cilia et al., 2016; Gan‐Or et al., 2008; Liu et al., 2016).