Look at the following article by Cort, summarizing the "demystifying medicine" broadcast with Dr. Alter and Dr. Lo: http://phoenixrising.me/?p=5158 It says: Look at the sentence in bold letters. Now, the contamination theory cannot explain that sentence - because even if the samples were contaminated, then the CDC's test, if it's indeed good at finding XMRV/MuLVs as they say it is, should have come back positive - because the test doesn't care if it's contamination or not (and only other tests, like the mtDNA tests, would have shown that the result is probably due to contamination). One explanation could be that the tests were being shipped at wrong conditions - but I guess that both the scientists from the FDA and from the CDC insisted that the tests would be shipped in conditions which they believe are sutiable - and since all of the scientists that came up with negative results refuse to recognize that it's very possible that some variation, which seems not important to them, from the original methods described in the "Science" paper, are resposible for the discrepant results - it would seem that they would also think that this is not the case here, meaning that the shippment conditions are not responsible for the CDC not finding any positives in samples that the FDA found all of them to be positive. So, that leaves us with a very high probability that the following is the reason for the dicrepancy here: The CDC's tests, performed on the samples sent by the FDA, couldn't find a virus that was actually there (contamination or not).