At first, cancer is a quiet disease. Inside the body, cells are aggressively multiplying out of control, changing everything. But on the outside, there's nothing special to see or feel. Not yet. For Guardant co-CEO Helmy Eltoukhy, that invisibility looked like an engineering challenge. What if cancer could be detected early - through blood tests - before you even knew it was there?
Current medical guidelines have us screening for only five cancers, and one at a time. A new test, from a startup called Grail, has identified fifty cancers, with a remarkably low rate of false positives.