ORIP seeks to provide better models of human disease conditions of interest to multiple NIH Institutes and Centers. Today’s biomedical researchers have a wide variety of model systems from which to choose when studying human biology and disease states. Therapeutic approaches can be tested for safety and effectiveness in animal models prior to human clinical trials. New technologies that permit the construction of a mouse with a human immune system and other such constructs have resulted in model systems that are more precise and predictive of human pathologies.