There is a lot of talk about an experimental cancer vaccine.
A study has been published in the journal Nature Medicine that shows "promising results" in the test on a small clinical trial of patients with lymphoma.
The patients were treated at Mount Sinai Hospital in New York.
The treatment is referred to as a vaccine because it causes a person's immune system to fight the disease.
There will have to be larger trials before even going before the Food and Drug Administration for review.
Researchers created the treatment directly inside the tumour by injecting one tumour with a stimulant to recruit immune cells.
The activated immune cells then travel throughout the body.