Figure 2. Alignment of BK polyomavirus non-coding control region (BKPyV NCCR) isolates from different clinical specimens of patients with bladder cancer the prototypic NCCR sequence. The prototypic NCCR defined by Yogo and colleagues (31) is shown at the top of the figure, while nucleotide sequences of three variants, determined directly from malignant (low-grade) bladder tissue, urine and blood samples, are shown below in relation to the prototypic NCCR, with nucleotide substitutions indicated by bold highlighted letters and deletions identified by bold highlighted hyphens. The genotype/subtype corresponding to each isolate is also indicated. Blocks (P, Q, R and S) commonly used to denote archetypal NCCRs (5) are indicated under the NCCR sequences, while proven and putative binding sites for transcriptional factors are illustrated above the prototypic NCCR sequence. The O-block, containing the origin of replication, was omitted.