DLBCL from 66 newly diagnosed poor-risk patients, treated in two sequential prospective Dutch Hemato-Oncology Association (HOVON) trials, were studied retrospectively for expression of CD10, bcl6, MUM1/IRF4, bcl2, Ki67, and CD21+ follicular dendritic cells (FDC) by immunohistochemistry, and for the breakpoints of BCL2, BCL6, and MYC by fluorescent in situ hybridization (FISH). 