Schondorf et al. used this protocol to generate DA neurons from iPSCs obtained from PD patients with acid α-glucocerebrosidase (GBA1) mutation (15-20% TH +ve), in order to demonstrate the association of this mutation with dysfunctions in the autophagic/lysosomal system [114] (see Section 5.6 for more detail on GBA1 and Gaucher’s disease). The gene discussed is GBA1; the disease is Parkinson disease.