Interestingly, although ES is a cancer of low mutational burden, 12% of patients have CDKN2A deletion (48) an event that often leads to co-deletion of MTAP. MTAP is an enzyme that is part of the methionine salvage pathway that metabolically converts methylthioadenosine (MTA) to methylthioribose (MTR) and adenine ultimately leading to methionine regeneration. This evidence concerns the gene MTAP and Ewing sarcoma.