Some of the risk factors previously identified in the malignant HSCT setting [12, 14] were present in our cohort, such as age at HSCT < 3 years (100% of our osteochondroma cohort respectively) and male gender (90%), whereas other reported risk factors such as use of growth hormone replacement therapy, or busulfan-based conditioning regime were not found in our osteochondroma cohort. Here, GH1 is linked to Osteochondroma.