PBMCs from an additional seven patients (2 to 8, Table 1) with advanced Ewing sarcoma were analyzed for PTPRD germline mutations in all 35 exons (exons 11-45, ENST00000381196) using Sanger sequencing, as previously described.[11] Among these seven patients, five had wild-type PTPRD and two had PTPRD germline mutations: T781A and R995C. Here, PTPRD is linked to Ewing sarcoma.