There are two main risk factors for testicular cancer. The first is something called an undescended testicle. What does that mean? When we’re developing in the womb, the testicles actually start high up in the abdomen, near the kidneys, and they drop down to their eventual location in the scrotum. Occasionally they don’t make the full journey. And at birth it’s noticed that one or both testicles can’t be felt in the scrotum. That’s called an undescended testicle. Sometimes surgery is required to bring the testicle fully down in the scrotum, and sometimes they drop down further on their own. But this is a risk factor for ultimately developing testicular cancer. The other cause may be genetic. If we globally look at most cancers, about 20% of them have some kind of genetic or DNA mutation component. For testicular cancer, that number is much higher. In one study of over 10,000 patients, about 50% of testicular cancers were felt to be associated with some mutation. It was typically not one DNA mutation, but a combination of many.