FISH on metaphase chromosomes from the lymphoma patient (A), patient’s husband (B), and their daughter (C). Hybridization with an HHV-6–specific probe showed HHV-6 integration with symmetrical doublet signals at homologous sites of both chromatids. Arrow and arrow head indicate the hybridization signals on chromosome loci 1q44 and 22q13, respectively. Chromosomes were counterstained with propidium iodide.