Ludmil B. Alexandrov

Carrying a cancer mutation is normal; most mutant clones never become cancer. This means blood or tissue tests that look for driver mutations alone will produce false positives, and that the question of what tips a mutant clone into cancer (tissue environment, further hits, immune surveillance) is as important as the mutation itself.

There are not thousands of cancer genes, and any one patient's tumour is driven by only a few of them. That makes targeted sequencing panels sensible, but because most drivers are lost tumour suppressors, drugs exist for only a minority, which is why the same group turned to early detection.