Interesting that the XMRV positive findings in ME/CFS patients in this study are accepted as 'a given' and Merleir just moves straight on to discussing the immune system dysfunction measurements, ie the next stage. Most of the scientists at the recent XMRV Conference, as we know, are still stuck on stage 1, actually finding the XMRV and whether this proves anything. Good for Merleir. He may actually be proving direct causation in a round about way. Also, I wonder whether it is the HIV and/or the XMRV infection that directly causes the gut permeability, or whether these retroviruses incapacitate immune function to the point that fungal infections take root and damage the mucosal lining, or maybe both in a symbiotic kind of way?