The level of GCase observed in PBMCs does not change across the different genotypes (Fig. 2c), but LRRK2 G2019S PD patients exhibit a trend toward higher GCase protein level when compared to non-manifesting carriers (p = 0.0536, one-way ANOVA with Tukey’s post test), further suggesting that the interplay between LRRK2 and GCase may change upon the manifestation of the disease. The gene discussed is LRRK2; the disease is Parkinson disease.