PDL1/2 or BCL6 chromosome maps and cumulative risk of CNS relapse by PDL or BCL6 rearrangement. The maps display relative probe positions for break-apart assays, and representative rearrangement-positive cases are depicted, with arrows denoting nuclei. Images were obtained with an Olympus BX61 microscope, original magnification ×40, at room temperature, with ARIOL software, v3.4; (Genetix). The cumulative risk of CNS relapse (using competing risk analysis) among cases with or without a PDL1- or -2 (A) or a BCL6 (B) rearrangement, as determined by FISH.