COL1A1 and osteogenesis imperfecta: In vivo, 4‐PBA treatment improved bone abnormalities in a zebrafish collagen helix misfolding mutation (Col1a1a p.G736D) OI model,24 and in the Aga2+/− mouse model, where a Col1a1 frameshift mutation in the C‐propeptide results in failed procollagen I assembly.25