Genome structure of BKV. The transcription of both early and late coding regions proceeds in a bidirectional way from the Origin of Replication (ORI) within the Noncoding Control Region (NCCR). The transcriptional splicing regions are represented by dashed lines. The late coding regions encode structural proteins (VP1, VP2, and VP3), while the early coding regions transcribe the tumorigenic proteins (LTA and STA). The late coding regions also encode the non-immunogenic Agno protein. The expression of miRNA complementary to the 3= end of LTA has been shown to be involved in replication control of BKV (36).