I'll press on a bit...tight junctions also prevent the passage of water; looser junctions don't. Around the time of my onset, about 17 years ago, I spent a night at a friend's house. During the night, I felt a rapidly-growing itching, and a sensation that I can only describe in exactly the same way that many Morgellon's sufferers describe their onset event: like millions of tiny insects crawling around just under the skin. The sensation spread rapidly across my whole body within minutes. It was very weird and I've never felt anything like it, before or since. It was around this time that my symptoms began - and unfortunately I'm unable to place the events in sequence because they didn't seem so important then as they do now. But amongst the first of what I now recognise as the onset of my symptoms was the bizarre night-sweats. I'm not certain whether they came after the event I just described. (I also got persistent fungal infections soon afterwards, starting with athlete's foot, which I'd never had before...could tight junctions be significant in protecting against fungal infection?) But noting the function of tight junctions in preventing water from passing through, and noting that whenever my itching and gut issues worsen I get night sweats, and a return of the same sickly-sweet-smelling sweat that lingers for ages on towels...I'm wondering whether this sweat is related to some liquid passing through tight junctions that wouldn't normally get through. A bit more tenuous than the above observations perhaps...but I'm also reminded that my sister (also a long-term sufferer of "IBS/PVFS/CFS") now reports problems with 'water-retention'...could that phenomenon also be related to the function of tight junctions I wonder? Any information about tight junctions, I'm interested...perhaps the subject deserves a separate thread?