Furthermore, in FGF10 EX1mut/EX3mut transgenic mice with severe thyroid hypoplasia, allogeneic normal ECSs could induce orthotopic thyroid tissue regeneration when microinjected into the embryos of FGF10 EX1mut/EX3mut mice via blastocyst complementation (25). The gene discussed is FGF10; the disease is thyroid hypoplasia.