This invention regards the diagnosis and remedy of the cancer which utilizes the antibody, and the aforementioned antibody which are joined to the TM4SF20 protein. Namely, this invention, offers the medicine constituent (for example, anticancer agent and cancer diagnostic glaze) which designates the anti- TM4SF20 antibody, and the aforementioned antibody as the active ingredient.本発明は、TM4SF20タンパク質に結合する抗体、及び前記抗体を利用した癌の診断と治療に関する。すなわち、本発明は、抗TM4SF20抗体、及び前記抗体を有効成分とする医薬組成物(例えば、抗癌剤、癌診断薬)を提供する。