QRT-PCR analysis of RRM1, RRM2, and RRM2b represents fold change in RRM1, RRM2, and RRM2b mRNA expression in peripheral blood mononuclear cells 24-h post-treatment with 3-AP plus gemcitabine in patients 4, 16, 27 and 31. Fold change is relative to pre-treatment sample, and all samples were normalized to TATA-binding protein (TBP). There was a quantitative decrease in PBMC RRM2 mRNA expression after 3-AP/gemcitabine therapy in 3 of 4 patients evaluated, and variable effects observed in RRM1 and RRM2b