Flow cytometry profile showing green fluorescent protein (GFP)–positive cells.

Shown at the end of the infection protocol (A) and in peripheral blood leukocytes (B) of individual mice engrafted with virus-infected cells at week 6 after transplantation. WT transplant (left panels) or TGF-β1^−/− transplants (right panels). Percent of positive cells is given above each corresponding profile.