TGFB1 and osteogenesis imperfecta: TGFβ1 is a multifunctional protein with key roles in bone and muscle physiology; perturbations in the TGFβ1 signalling pathway are associated with multiple skeletal dysplasias (e.g. osteogenesis imperfecta type IV (OMIM 166220), acromicric dysplasia (OMIM 102370) and Loeys-Dietz syndrome types 1–5.