For years doctors have known that people with Down's syndrome have a lower risk of some cancers, except for leukaemia. Now a study in Nature suggests that a single gene on their extra chromosome provides some extra protection for them. Tests on mice appear to show that the gene prevents the development of solid cancerous tumours. This finding could lead to news ways to treat cancers. Writing in the journal, the researchers, led by Dr Sandra Ryeom, said: "It is, perhaps, inspiring that the Down's syndrome population provides us with new insight into mechanisms that regulate cancer growth and, by so doing, identifies potential targets for tumour prevention and therapy." ~ BBC, May 20