TGFB1 and osteogenesis imperfecta: TGFβ, MAPK and activin pathways are commonly disrupted in OI (Etich et al., 2020; Shi et al., 2018) and high levels of TGFβ are hypothesised to play fundamental roles in driving the pathogenic mechanisms that are observed in OI bone (Grafe et al., 2014; Bianchi et al., 2015; Greene et al., 2021).