Although we did not have access to the previously categorized tumor samples to directly test them by IHC, we developed an ensemble molecular classifier of MYC-driven DLBCL using the transcriptional profiles from a subset of our DLBCLs categorized as MYC IHC-High (i.e., >60% tumor cells positive) and MYC IHC-Low (i.e., <50% tumor cells positive) and applied this ensemble classifier to the previously published transcriptional profile datasets (Supplementary Methods S1). The gene discussed is MYC; the disease is neoplasm.