Mice are the laboratory animal species most closely related to humans in which the knockout technique can be easily performed, so they are a favorite subject for knockout experiments, especially with regard to genetic questions that relate to human The Knockout Mouse facility at the National Cancer Institute - Frederick provides services with the production of genetically engineered mouse models with loss-of-function mutation through homologous recombination. By removing a certain gene and studying the mouse for any resulting differences, researchers can infer the probable function of that particular gene. Examples of research in which knockout mice have been useful include studying and modeling different kinds of cancer, obesity, heart disease, diabetes, arthritis, substance abuse, anxiety, aging and Parkinson's disease. Knockout mice also offer a biological and scientific context in which drugs and other therapies can be developed and tested
