FGFR3 and thanatophoric dysplasia: TYRA-300 was studied in a Tg-CMVCre/+/Fgfr3Y367C/+ mouse model, which, while corresponding to the human FGFR3 Y373C mutant responsible for thanatophoric dysplasia, type I, displays a phenotype similar to that of human ACH and has been previously used to test the preclinical efficacy of other therapies in this context (21, 28, 29, 34–36).