FACS analysis of irradiated recipients rescued by transplantation of WKM cells carrying a β-actin^eGFP transgene. (A) Visualization of kidney scatter populations (left) shows that 97% of myeloid cells (green gate) in recipient 1 (dotted green histogram, right panel) and 95% of myeloid cells in recipient 2 (solid green histogram, right panel) are donor-derived at 4 weeks after transplantation based on expression of the GFP transgene. (B) Similar analysis of 2 transplant recipients at 8 weeks after transplantation shows 89% and 86% donor-derived myeloid cells. Erythroid cells (red gate, left panels) do not express the β-actin^eGFP transgene and were used as internal negative controls for GFP expression (solid red histograms, right panels).