<p>Base compositions of the 4-bp target site duplication (positions D1 to D4; demarcated by the thick vertical lines) and 10 bp upstream (positions −1 to −10) and downstream (positions +1 to +10) of the direct repeat were calculated. The datasets include the 13 integration sites with correct 4-bp direct repeat (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0010255#pone-0010255-t001" target="_blank">Table 1</a>), 472 integration sites from acutely infected DU145 cells (GenBank accession numbers EU981292 to EU981799) and 14 integration sites from human prostate cancer tissues (GenBank accession numbers EU981800 to EU981813) <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0010255#pone.0010255-Kim1" target="_blank">[14]</a>. Integration occurs between positions −1 and D1 on the top strand, and between positions D4 and +1 on the bottom strand (blue arrows). Any base in a position that is significantly overrepresented than the random dataset (<i>P</i><0.0001) is highlighted in green, while any base in a position that is significantly underrepresented than the random dataset (<i>P</i><0.0001) is highlighted in red.</p