Medical advances to tackle devastating diseases often rely on animal models whose genes have been modified to closely resemble human biology. Today, this process takes years of expensive and inefficient selective breeding that slows research and delays health breakthroughs. MAGER will address this research bottleneck by developing rapidly genetically humanizing models through an emerging technology called trophectoderm isolation. If successful, the MAGER team will facilitate a way to humanize models in months, not years--improving animal model welfare, saving research dollars, and bringing more affordable and accessible therapies for serious human diseases.