GBA1 and Parkinson disease: To determine whether quetiapine could modulate wild-type GCase levels and activity in human neurons, we examined iPSC-derived dopaminergic neurons from a PD patient line harboring the heterozygous 84GG GBA1 mutation (c.84dupG frame-shift mutation) that results in complete loss of mutant GCase and reduced wild-type protein from a single copy of the wild-type GCase allele and used a CRISPR-corrected isogenic line as control.