Neurology journals have been flooded with review articles on biomarkers and “precision medicine.” Many start with the standard disclaimer that a major challenge for the development of biomarkers is the numerous biological processes responsible for Parkinson’s and Alzheimer’s diseases. One such disclaimer goes like this: “ … [finding a biomarker or a drug to work on all Parkinson’s patients] is wrong because (1) Parkinson’s disease is not a single disease, and (2) no two individuals have the same biological makeup.” So far so good. However, the very next paragraph starts with: “Now let us summarize the work done to date on validating biomarkers of progression for Parkinson’s disease.” No further mention is made of which disease these efforts pertain to. (Presumably all!) These articles invariably surrendered to the luring power of sophisticated analytic methodologies to overcome the shortcomings mentioned in the disclaimer.