Quantification of B7.1 and B7-H1 in persistent leukemic cells. (A) Time course of B7.1 and B7H-1 expression by persistent leukemic cells measured by flow cytometry. Thin lines indicate isotype control. (B-C) Real-time PCR quantification of (B) B7.1 mRNA and (C) B7-H1 mRNA in persistent leukemic cells taken from naive mice or mice that had been vaccinated with DA1-3b cells transduced with various plasmids. Error bars indicate standard deviation.