Tumor genome sequences and mouse “avatars” may help Mayo Clinic researchers identify the best chemotherapy for individual breast cancer patients in a new study dubbed the BEAUTY project.

In the first phase of the Breast Cancer Genome Guided Therapy Study, Mayo Clinic researchers will sequence the genome of tumors from 200 women with breast cancer. The study will examine the genome both before and after chemotherapy to look for mutations that may bestow cancer cells with one of their most menacing talents—the ability to develop resistance to chemotherapy.

In the second phase of the trial, the researchers will target resistant tumors with drugs tailored to a tumor’s particular mutations. “This is already sort of happening, but not on the scale that we are envisioning at Mayo. We want to make this a standard part of practice to offer to every woman with a high-risk tumor,” said Richard Weinshilboum in a video statement. Key to this kind of personalized therapy is the plummeting cost and time needed to sequence DNA.

Researchers will also look to so-called mouse “avatars” for help in treating every cancer patient as an individual. Cells from each participant’s tumor—before and after chemotherapy—will be transplanted into mice. Clinicians can then test the efficacy of different cancer therapies on these “avatars” of each patient’s cancer.