Cancer cells come pre-programmed to execute a well-defined cascade of changes, seemingly designed to facilitate both their enhanced survival and their dissemination through the bloodstream. There is even an air of conspiracy in the way that tumours use chemical signals to create cancer-friendly niches in remote organs.

Astonishingly, in spite of decades of research, there is no agreed theory of cancer, no explanation for why, inside almost all healthy cells, there lurks a highly efficient cancer subroutine that can be activated by a variety of agents - radiation, chemicals, inflammation and infection.

Studying cancer could provide huge insights for astrobiologists into the nature of life itself.

Cancer is like another form of life. It's closely related to healthy life. A healthy body is one form of life. Cancer is in a way nature's experiment with life.