Itoh, M et al. Nat. Commun. 10, 2244 (2019)

Recent developments in stem cell technology and tissue engineering have opened new avenues for regenerative medicine. Tissues and organs such as vascular grafts, liver, and myocardium have been successfully produced from human-derived cells and implanted in small animals. However, before translation to the clinics, human cell regeneration strategies need to be evaluated in large animals. A study describes a new mini-pig model in which an immunodeficient state was induced by removing the major immune organs and administrating immunosuppressive therapy. This operational immunodeficient pig (OIDP) model enabled the long-term accommodation of an artificial human vascular graft that was rejected in a conventional immunosuppressive pig (CISP) model. OIDPs might become an invaluable tool for the evaluation of preclinical human cell regeneration strategies.