One theory, which may explain its failure against breast cancer, is that there may be tissue-specific proteins that spur tumor growth in the absence of VEGF.
Many believe that if a way can be found to grow and harvest these cells, they can be used as replacement tissue to combat a variety of human diseases and ailments, from diabetes to organ failure.
Inflammation and fibrosis - scarring - of the liver tissue, which affects about 10% of the UK population, can cause cirrhosis or liver failure and lead to cancer if diagnosis is delayed or if left untreated.
The virus that infected him bears a 99.5% similarity to one isolated from the lung tissue of a 60-year-old man from Saudi Arabia who died this summer after suffering respiratory and kidney failure, the WHO said.