The spreading of different types of cancer cells to the brain, forming brain metastases, is the main cause of morbidity and mortality associated to cancer. Now, a new study led by Cláudia C. Faria, principal investigator in the group of João Taborda Barata at the Instituto de Medicina Molecular João Lobo Antunes (iMM; Portugal) and neurosurgeon at the Hospital Santa Maria (HSM, CHULN, Portugal), and published today in the scientific journal Cell Reports Medicine* created a library of models to study brain metastases that recapitulate the disease in humans. These models can be a relevant tool to understand the disease and discover new therapeutical approaches tailormade to each patient.