If it is confirmed that patients have different levels of certain molecules in the skin even before Parkinson’s symptoms manifest themselves—even though the average person cannot detect the smell (almost no one has Joy’s sense of smell)—it would then be possible to take a sample of this skin fat, analyze it and see if a person has the disease or not. Thus, even when it is still under study, it is possible that something as subtle as odor could have a huge impact on Parkinson’s research.