That's not exactly what I said. I said it relates to officially diagnosed CFS patients. But in my opinion, it probably relates to historically defined ME patients. I am of the opinion that most CFS patients with immunological symptoms are ME patients, based on the historical definitions of ME. I think that even Byron Hyde only initially looks for basic things in his patients, such as type of onset, patient-reported symptoms, immunological issues. But I agree that unless someone does some high quality research in this area, then we won't know if this is so. The problem is, what diagnostic criteria would we use to find out? The Nightingale definition has not been peer reviewed. But I would be interested for Byron Hyde to diagnose the WPI cohort using his definition, to see how many of the patients he considers have ME. I'm not sure what you mean... In the UK we have an official condition called CFS/ME, but we do not have any official diagnostic criteria for ME, as far as I am aware. What are the official diagnostic criteria for ME? Is there an international set of diagnostic criteria? Do any countries diagnose ME officially?