CYP1A2 and Parkinson disease: Based on the publicly available Genome Aggregation Database and our previous study, we identified 5 CYP1A2 SNVs and 3 CYP2E1 SNVs associated with caffeine metabolism.18 There were no significant differences in the frequencies of any SNV among patients with PD, PSP, and MSA or HCs (Supplementary Table 9).