AIM: The Ewing sarcoma family of tumors (ESFT) is a group of malignant small round cell neoplasms of bones and soft tissues closely histogenetically related. Methylthioadenosine phosphorylase (MTAP) deficiency has been recently associated with increased tumor aggressiveness and poor outcomes in different types of neoplasms. However, the expression of this biomarker and its biological role in ESFT remain largely...