Several mAbs have been tested as single agent in phase I or II clinical trials, mainly in patients with osteosarcoma, including trastuzumab to target human epidermal growth factor receptor 2 (HER2) (24), cexutimab to target the epidermal growth factor receptor (EGFR) (25), glembatumumab-vedotin to target the glycoprotein non-metastatic B (GPNMB) (26), and dinutuxumab to target disialoganglioside GD2 (27). Here, ERBB2 is linked to osteosarcoma.