Baseline levels of p-ERK and p-AKT in responders versus nonresponders. Baseline (pretreatment) expression levels of phosphorylated ERK and AKT from bone marrow samples were measured and normalized, as described in “Patients, materials, and methods.” No difference in baseline expression levels of p-ERK or p-AKT was detected between responders and nonresponders. Horizontal bars represent median p-ERK and p-AKT normalized levels.