Integration site analysis by 454 high-throughput sequencing. Results of high-throughput sequencing of integration sites in samples taken 2, 4, 6, and 9.5 months after transplantation are shown. (A) Integration sites from posttransplantation samples were assigned to their closest gene function as annotated in PantherDB and checked for repetitive detection. The framed area in the middle of each diagram represents a highly persisting fraction of integration sites that was detected in 3 to 4 different time points. (B) Integration sites from panel A were analyzed according to their biologic function (“apoptosis,” “oncogenesis,” “signal transduction,” and “unclassified”), and their distribution plotted over time. (C) Comparison of the group-specific distribution of gene functions (“apoptosis,” “oncogenesis,” “signal transduction,” and “unclassified”) in the framed area and in the whole dataset from panel A. * P < .05 by Fisher exact test. n.d. indicates not detected.