Petosemtamab (FUT8-KO) is a variant of Petosemtamab with the fucosyltransferase 8 gene (FUT8) knocked out. Petosemtamab is a monoclonal antibody (mAb) targeting EGFR (with a Kd of 0.22 nM) and LGR5 (with a Kd of 0.86 nM). This antibody disrupts EGFR signaling and causes receptor degradation in LGR5+ cancer cells. It is applicable in research on solid tumors such as head and neck squamous cell carcinoma (HNSCC) and metastatic colorectal cancer (CRC).