1.   Integration of the viral genes Nevertheless, some viruses that lack known cancer genes have also been found to induce cancer.

2.   It seems likely that they achieve this by integration of the viral genes next to the cellular copy of a cancer gene.

3.   Once viral genes have become integrated into chromosomes their activity is usually altered or totally suppressed.

4.   Proteins made by these viral genes are chewed up and displayed in the normal way when dendritic cells meet the altered bacteria.

5.   These discoveries raise intriguing questions about the relationship between viral genes and the normal genes of the cell.

6.   And when those viral genes are activated, the cell starts producing more HIV.

7.   Cells picked up the DNA and used those viral genes to make viral proteins.

8.   Current viral gene carriers take hours and sometimes days to deliver their genetic cargo, and pose some risks.

9.   Harley and Shay have already had some success engineering viruses to carry telomerase genes, instead of harmful viral genes, into cells.

10.   So far the indication is that all the viral genes are of avian origin.