A Derived Xenograft (DX) mouse model, also known as a Patient-Derived Xenograft (PDX) model, is a type of preclinical animal model used in cancer research. It involves implanting human tumor tissue (usually obtained from a patient) into immunocompromised mice, which allows researchers to study the growth and response of the tumor in a more physiologically relevant environment.

The DX mouse model is considered to be a more clinically relevant model than traditional cell line-based models because it retains the genetic and biological characteristics of the original tumor. By studying the tumor in the DX mouse model, researchers can identify potential drug targets and test the effectiveness of various treatments in a more realistic setting. The model can also be used to study tumor heterogeneity, drug resistance, and other aspects of tumor biology that are difficult to model in vitro.

The DX mouse model has limitations, such as the possibility of genetic drift and the lack of a functional immune system in the mice, but it remains an important tool in cancer research and drug development.