Summary of gene transfer levels in dogs transplanted with gene-modified CD34-enriched marrow cells. Dogs E585 (▴) and E617 (⧫) received gene-modified cells transduced in the presence of FLT3L, cSCF, and MGDF (FSM), and dogs E649 (▪) and E680 (•) received cells transduced in the presence of FLT3L, cSCF, and cG-CSF (FSG). PCR-negative samples (<0.01%) are plotted in the shaded area. The difference between the 2 groups is statistically significant, P= .02 (Student’s t-test).