No irradiation required: The future of humanized immune system modeling in murine hosts.

Immunocompromised mice are an essential tool for human xenotransplantation studies, including human haematopoietic stem cell (HSC) biology research. Over the past 35 years, there have been many advances in the development of these mouse models, offering researchers increasingly sophisticated options for creating clinically relevant mouse-human chimeras. This addendum article will focus on our recent development of the "NSGW" mouse, which, among other beneficial traits, is genetically modified to obviate the need for myeloablative irradiation of the animals. Thus, the complicating haematopoietic, gastrointestinal, and neurological side effects associated with irradiation are avoided and investigators without access to radiation sources are enabled to pursue engraftment studies with human HSCs. We will also discuss the topics of transgenics, knock-ins, and other mutants with an overarching goal of enhancing chimerism in these animal models.