Human U-87 MG glioma tumor cells expressing green fluorescent protein were xenografted orthotopically into an athymic nude mouse brain. The mouse brain was cryo-imaged and reconstructed in 3 dimensions to show the human U-87 MG glioma main tumor mass (pseudocolored green), dispersed tumor cells (pseudocolored yellow), and the mouse brain vasculature (pseudocolored red). Cells from the U-87 MG glioma tumor (yellow cells) migrated and dispersed on a nearby blood vessel. For details, see the article by Burden-Gulley and colleagues on page 5932 of this issue.