Down Syndrome Yields Key Cancer Clue

Solid tumors are very rare in people with Down syndrome. Why? The answer almost certainly lies among the 231 extra genes they inherit with their extra copy of chromosome 21. People with Down syndrome rarely get diseases linked to the overgrowth of blood vessels. One of the genes on chromosome 21 encodes a protein that blocks a factor needed for blood vessel growth. This protein, DSCR1, is overproduced in people with Down syndrome. Web MD