Postnatally, Prop1:Cre;BrafV600E/+;RosaTM/+ (Prop1:Cre;BrafV600E/+ thereafter) pups showed clear signs of severe hypopituitarism with dwarfism and growth failure, and they died prematurely around weaning compared to their Wt littermates (Fig. 3a–c). Here, PROP1 is linked to Severe short stature.