With What Should We Replace Nonhuman Animals in Biomedical Research Protocols?

Historically, most discussions about nonhuman animal experimentation consider what has become known as the 3 R's: refinement, reduction, and replacement. Refinement and reduction receive the most attention, but recent modeling advances suggest that suitable replacement of nonhuman animal testing would bolster human research and increase translatability to human health outcomes. This article discusses these modeling advances and advocates their use, especially as replacements to nonpredictive nonhuman animal protocols, and discusses growing momentum in biomedical research communities and federal agencies that favors replacement of animal testing.