Depatuxizumab is a reference monoclonal antibody targeting the epidermal growth factor receptor (EGFR, also known as ERBB1 or HER1). It is used in research and bioassays to mimic the therapeutic antibody in the treatment of glioblastoma, an aggressive brain cancer. The antibody binds specifically to EGFR on tumor cells, particularly those overexpressing EGFR or harboring the EGFRvIII mutation, thereby inhibiting EGFR signaling pathways that drive cancer cell proliferation. In its conjugated form (depatuxizumab mafodotin, an antibody-drug conjugate), it delivers a cytotoxic agent (monomethyl auristatin F) directly to cancer cells, sparing healthy tissue and reducing side effects compared to traditional chemotherapy. This reference antibody supports the evaluation and development of such targeted therapies, which have been assessed in clinical trials for newly diagnosed and recurrent glioblastoma.