To analyse if serpinA1 could serve as a predictive biomarker for dementia in PD patients we stratified our PD patient cohort into PD with intact cognitive function (PD) and PD with mild cognitive impairment (PD-MCI) and analysed selected acidic peaks (Fig. 3C), especially the normalized peak 0 (Fig. 3D). This evidence concerns the gene SERPINA1 and Parkinson disease.