For all the people who think John Coffin was part of some sort of cover-up, that is what he had to say in October 2009 about this:
The virus that you isolate is infectious for a number of human cell lines. It’s particularly infectious for the prostate cancer cell lines as was mentioned and also for b-cell and t-cell derived lines and for fresh activated PBMCs (Peripheral Blood Mononuclear cells) which are basically a mixture of b-cells and t-cells.
Later, at minute 137:One of the big worries in this kind of study over the years is these viruses are actually common contaminants of human cell lines. They infect prostate cancer cell lines very nicely, and these are often isolated by passage through nude mice. Once the nude mice have this infectious provirus, this virus can then infect the tumor. There are repeated reports over and over again of human tumor cell lines that have picked up these viruses in this way and so when one first sees this it’s a major concern.
And BTW, that XMRV can infect a cell line is no proof that XMRV is a human pathogen.