COL1A1 and osteogenesis imperfecta: Although the small number of patients used for the study does not allow us to make any definitive conclusion, performing protein quantification by quantitative tandem mass tags (TMT) isobaric labeling and REVIGO and MetaCore data processing, we identified a particular fibroblast protein profile differentiating type III from type II OI probands, regardless of the causative mutation and the affected COL1A1 or COLA2 gene.