![488635633 488635633](https://api.time.com/wp-content/uploads/2015/01/488635633.jpg?quality=85&w=2400)
Researchers have found that bad luck plays a major role in determining most types of cancer, rather than genetics or risky lifestyle choices such as smoking.
The results, published in the journal Science on Thursday, found that random DNA mutations that amass in the body when stem cells divide into various tissues cause two thirds of cancers.
After examining 31 cancer types, researchers found 22 were from mutations in stem cells that could not be prevented.
Cancers that could be explained with biological bad luck included pancreatic, leukemia, bone, testicular, ovarian and brain cancer.
But the researchers say lifestyle choices such as avoiding smoking, eating healthily and staying out of the sun will help to prevent certain cancers, just not all of them.
Read next: Medicine Is About to Get Personal
More Must-Reads from TIME
- Why Biden Dropped Out
- Ukraine’s Plan to Survive Trump
- The Rise of a New Kind of Parenting Guru
- The Chaos and Commotion of the RNC in Photos
- Why We All Have a Stake in Twisters’ Success
- 8 Eating Habits That Actually Improve Your Sleep
- Welcome to the Noah Lyles Olympics
- Get Our Paris Olympics Newsletter in Your Inbox
Write to Helen Regan at helen.regan@timeasia.com