Metabolomic analyses of the LRRK2 Cohort Consortium (LCC) samples identified caffeine, its demethylation metabolites, and trigonelline as prominent markers of resistance to PD linked to pathogenic LRRK2 mutations, more so than to idiopathic PD (Crotty et al., 2020). The gene discussed is LRRK2; the disease is Parkinson disease.