Multilineage differentiation in representative NOD/SCID mice receiving transplants of CD34⁺ progenitors transduced in the presence of various ABC transporter inhibitors. Flow cytometric analysis of cells isolated from the bone marrow of mice that received transplants of human CD34⁺ progenitor cells transduced with no drug or in the presence of quinidine, diltiazem, or ritonavir. The proportions of GFP-positive human cells are depicted in the top right quadrant.