Cancers often acquire loss-of-function mutations in tumor suppressor genes, leading to reduced or absent protein products. This creates a challenge for targeted therapies, as there are no cancer-specific proteins for drugs to bind. To address this, GRETTA, a computational tool, has been developed to map genetic networks of cancer-associated genes and predict targetable vulnerabilities (i.e., synthetic lethalities) in cancer cells with specific somatic mutations. The goal is to evaluate how GRETTA can inform and enhance precision cancer medicine.