PROBLEM TO BE SOLVED: To provide a tumor specific molecule that recognizes deletion mutants of epidermal growth factor receptor (EGFR) for better diagnosis and treatment of human and animal cancer.SOLUTION: Provided is an isolated human monoclonal antibody that specifically binds to a deletion mutant of EGFR, especially, to type III deletion mutant(EGFRvIII) and peptides including LEEKKGNYVVTDHC sequence. Also provided is a therapeutic agent for cancer associated with epidermal cell growth, using the antibody to which a toxin is combined. Also provided are a method for inhibiting cell growth related to expression of EGFRvIII, and a method for treating mammals including humans suffering from cancer associated with epidermal cell growth by using the antibody.【課題】ヒト及び動物の癌のより良い診断及び治療のための上皮成長因子受容体(EGFR)の欠失型変異体を認識する腫瘍特異的分子を提供する。【解決手段】EGFRの欠失型変異体、及び特にタイプIIIの欠失型変異体、EGFRvIII及び配列LEEKKGNYVVTDHCを含むペプチドと特異的に結合する単離したヒトモノクローナル抗体。前記抗体を毒素と結合させた、上皮細胞増殖を伴う癌の治療剤。EGFRvIIIの発現と関連する細胞の増殖を阻害する方法、上皮細胞増殖を伴う癌に罹患しているヒトなどの哺乳動物を前記抗体によって処置する方法。【選択図】なし