Claus R, Lucas DM, Ruppert AS, et al. Validation of ZAP-70 methylation and its relative significance in predicting outcome in chronic lymphocytic leukemia. Blood. 2014;124(1):42-48.

On page 43 in the 3 July 2014 issue, there is an error in the text. The first sentence of “Methods” reads, “Peripheral blood was obtained from asymptomatic, untreated CLL patients.” However, a subset of the patients (25% in the cohort used for this study) had been treated prior to sample collection, and therefore that sentence should have read, “Peripheral blood was obtained from CLL patients.” ZAP-70 expression did not vary over time, and no conclusions from this study are affected.