Dr Theresa Nahreini for assistance with cell culture and FACS
analysis. This research was supported by the University of
Colorado Boulder and the Medical Research Council (MRC Unit
programme U105178803). A.G.T is funded by a Cesar Milstein
Scholarship from the Darwin Trust of Edinburgh, Scotland. HeLa
cells were a generous gift from Katie Robinson and Christina
Dalby of miRagen Therapeutics, Boulder, CO.
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