Cell-surface phenotype of UCB-derived and PB-derived T cells before and after genetic modification. Multiparameter flow cytometry was performed on mononuclear cells from peripheral (periph) and cord blood (Umb) and genetically modified (GM) T cells that had been propagated for an average of 10 weeks under cytocidal concentrations of hygromycin B. Isotype-matched fluorescent mAb was used to establish the negative gates. The percentage of cells in each quadrant is shown.