Although the n is too small for comparative quantitative studies, the levels of autoantibodies in CSF in 5 healthy non-PD patients of our cohort were 2.32 × 10−2 U/mL ± 0.538 × 10−2 (SD) for AT1-AA, and 4.43 × 10−2 U/ mL ± 3.37 × 10−2 (SD) for ACE2-AA. This evidence concerns the gene ACE2 and Parkinson disease.