In addition, iPSC-derived mesenchymal stem cells from fibroblasts of OI patients carrying glycine mutations of COL1A1 (c.1814G > C) and COL1A2 (c.1072G > A) showed increased expression of UPR genes leading to increased apoptotic cell death [25]. This evidence concerns the gene COL1A1 and osteogenesis imperfecta.