In this present study, we used hybridoma technology with humanized transgenic mice to develop a fully human anti‐PTGFRN monoclonal antibody (8C7), when conjugated to the toxic payload Duocarmycin, shows efficacy in inhibiting tumour formation in xenograft mouse models of epidermoid carcinoma, paediatric medulloblastoma, and mesothelioma cancers. The gene discussed is PTGFRN; the disease is neoplasm.