These were most significant in the Broadman’s area 9 neurons where OXR1 was 5.3-fold lower in the Parkinson’s patients and in the posterior cingulate cortex pyramidal neurons where the Parkinson’s patients without dementia exhibited a 3.0-fold reduction in OXR1 mRNA and those with dementia showed a 2.0-fold reduction. Here, OXR1 is linked to Parkinson disease.