The June 10, 2013, article by Marcucci et al, entitled "Clinical Role of microRNAs in Cytogenetically Normal Acute Myeloid Leukemia: miR-155 Upregulation Independently Identifies High-Risk Patients" (J Clin Oncol 31:2086-2093, 2013), was published online May 6, 2013, with the Data Supplement missing. This has been uploaded as of June 6, 2013. Journal of Clinical Oncology apologizes for the mistake.