Cancer has become the leading cause of death in women, surpassing heart diseases. In males
it takes a second place. The disease burden is large and grows as a result of aging of the
population, especially in western countries. Cancer research in the past has led to a better
understanding of treatment and prognosis. Nevertheless, despite substantial efforts in this
research field, the pathogenesis of cancer is still largely unclear.
Since long it has been recognized, that cancer is not merely one disease, but ha
