I'm not convinced that the separation of ME and CFS is straightforward either. Even the ICC has subsets, such as 'atypical ME'. And as floydguy highlighted, however closely matched our illnesses are, we all display slightly different symptoms. So do we have the same illness with different symptoms, or different illnesses with very similar symptoms? Many of the researchers are now using both Fukuda and CCC. And hopefully they will start using ICC soon as well. So it will be possible in those studies to see how the research results match up to patients within each cohort. For example, they might discover that certain biomarkers are relevant only to CCC patients, and not Fukuda, or the other way around. But if any biomarkers end up actually being used successfully, then the various diagnostic criteria may become less important, because certain biomarkers may be able to separate patients into cohorts, and then each cohort can be treated and researched upon separately. Referring back to what floydguy said, they may be able to separate patients with primary endocrine abnormalities from patients primarily with immune abnormalities, hypothetically, if appropriate. So the biomarker approach is a completely different and novel approach to cohorts, which could bi-pass the existing diagnostic criteria. I think the various diagnostic criteria are still very important, but I'm just exploring potential ways forward.