FIGURE 1.

The possible contribution of viral sequences in the genome to cancer development. (A) Overview of possible functions of genomic viral sequences. Viral sequences in the genome could function as a gene regulatory DNA element (red), a functional RNA (green) or a protein (blue), all of which can contribute to cancer development. (B) HBV insertions in the genome. HBV insertions may enhance TERT promoter activity, have a recombinogenic effect or produce a viral-host chimeric RNA with an oncogenic potential. (C) EBLNs in the genome. The hsEBLN-2 protein may be involved in mitochondrial function, whereas the hsEBLN-1 protein may regulate microtubules. The hsEBLN-1 RNA has also been shown to regulate tumor-related genes.