As cancer researchers expand the frontiers of their understanding of the basic science of cancer, biotech companies are using what they’ve already learned to mobilize the human immune system against cancer.

In 2017, Moderna, in partnership with pharmaceutical giant Merck, announced plans to start human trials with a personalized vaccine that targets solid tumors. To make a specific vaccine for each patient, they start by sequencing the DNA of the patient’s healthy cells and cancerous ones. By comparing the two, they identify hundreds, and sometimes thousands, of mutations in the cancer cells.

Then they use AI to choose 34 mutations in each patient most likely to elicit a strong response from the immune system. To train the algorithms, the companies have partnered with university medical centers to gain access to biopsy samples.