We are merging our knowledge of embryonic development with our knowledge of cancer to build the next generation of cancer diagnostics. Our hypothesis is that many cancers are ultimately developmental diseases, with activation of normal embryonic programs in the wrong time and place. We are merging datasets cataloging mammalian development with datasets cataloging cancer to build a comprehensive developmental map of human tumors. We can use these maps to build predictive machine learning models that can aid diagnosis of cancers in the clinic. This will enable better precision medicine.