Supported by the Michael J Fox Foundation we established a biorepository of blood cells from G2019S LRRK2-PD patients recruited at the Hospital Clínic de Barcelona (Barcelona). Using this cohort, we performed a phospho-proteomic pilot study by mass spectrometry and identified a differential combination of phosphorylated proteins associated with the G2019S mutation. Here, we aim to validate and expand these findings using additional G2019S and R1441G cohorts (PMID: 35049090 By state-of-the-art DIA phospho-proteomics we aim to validate and expand our preliminary findings in additional G2019S and R1441G LRRK2 cohorts of similar design, size, and blood cell collection methods collected at additional centers in Spain (Hospital de Valdecilla in Santander, Hospital de Donostia in San Sebastian). We expect to identify differential protein phosphorylation changes in LRRK2-PD patients affected by the G2019S and R1441G mutations that could be useful as LRRK2 pharmacodynamic biomarkers. In asymptomatic LRRK2 mutation carriers, we will explore the presence of these phosphorylation changes and evaluate their applicability as early disease biomarkers.