TGFB1 and osteogenesis imperfecta: Due to the pathophysiological role that TGFβ appears to play in OI and the ability of Losartan to inhibit TGFβ-induced effects in other conditions, we hypothesised that losartan would reduce TGFβ signalling in cellular and mouse models of OI and that losartan would reduce bone resorption and increase bone mass providing a rationale for future use of this agent in OI patients.