The genetically engineered Factor 8 is made in hamster cells.

In fact, Dr. Levine said, it was by probing a tumor virus infection in hamster cells that he and his colleagues discovered p53.

He found that the hamster cells began making p53 to stop dividing and so protect themselves from the virus.

He developed the CHO cell line from Chinese hamster ovarian cells for this work.

The cells fuse together to form tissue, and tube formation has been demonstrated with ovarian hamster cells.

By contrast, conventional production in hamster cells can yield small amounts of protein in a few months, allowing clinical trials to begin more quickly.

But the shift to hamster cells added an extra financial burden for Pharming and undercut its claims for its own technology.

Amgen produces the drug by splicing the human erythropoietin gene into hamster cells, which then produce the protein.

After all, society accepts drugs made by putting human genes in hamster cells, even though this crosses species barriers as much as agricultural biotechnology does.

When a copy of human chromosome 1 was introduced, the immortal hamster cells began to show signs of aging.