Nucleotide alignments of XMRV integration site sequences derived from patients' prostate cancer tissues and the experimentally infected human tumour cell line DU145. Panel (A) shows the alignment of sequence EU981808 (patient 122-derived) and sequence GU816103 (DU145 cell line-derived). Panel (B) shows the alignment of sequence EU981810 (patient VP268-derived) and sequence EU981678 (DU145 cell line-derived). The initial 169 nt segment of sequence EU981678 is not shown as it includes a repeat within the XMRV sequence which is not covered by the much shorter EU981810 sequence and is therefore redundant for purposes of alignment. Upper case letters represent the XMRV LTR sequence and lower case letters represent the flanking human chromosomal sequence. Note that the viral 3' ends terminate with a conserved CA dinucleotide.