This predictive accuracy is in line with other blood biomarkers for PD—e.g., uric acid16 and urate,17 apolipoprotein A1,18 and α-synuclein transcripts.19 For example, using three study cohorts α-synuclein was found to be lower in blood of de novo PD patients with an average AUC of 0.60. This evidence concerns the gene APOA1 and Parkinson disease.