At its very core, cancer is a disease caused by DNA errors.
Within tumour cell DNA, there are a multitude of mutations that guide growth and make it difficult for the body to repair or destroy the tumour. But this doesn't stop the body's immune system from trying.
This contest between the immune system and cancer is complex, and one that Cancer Research UK researchers on the TRACERx project have been working to unpick. Previously, they've shown how tumour cells evolve to adapt to the immune system "micro-environment" surrounding them. But the team knew that it wasn't simply a one-way process.