A human antibody or a functional fragment thereof having specific binding ability to CD98 which is derived from the cell membrane of cancer cells and is in the form of a complex with a protein having an amino acid transporter activity (for example, LAT1) is disclosed. This antibody binds to CD98 in the form of a dimer with LAT1 on the surface of cancer cells, specifically attacks cancer cells expressing CD98 via the immune system by ADCC or CDC, and further inhibits amino acid uptake of the cancer cells via LAT1, to suppress growth of the cancer cells. Accordingly, a preventive and therapeutic agent for cancer comprising this antibody or a fragment thereof, which acts on various cancers, is specific to cancer, and causes no side effect, is provided.本發明揭示一種對CD98具有特異性結合能之人類抗體及其功能性片段，該CD98係來自癌細胞的細胞膜且與具有胺基酸輸送活性的蛋白質(例如LAT1)形成複合物。該抗體與LAT1及於癌細胞表面上形成二聚物之CD98結合，且利用ADCC或CDC之免疫系統對表現CD98之癌細胞進行特異性攻擊，進而抑制癌細胞經由LAT1對胺基酸之攝取，藉此抑制其增殖。因此，本發明提供一種含有該抗體或其抗體片段而成之作用於多種癌、又對癌無特異性副作用之癌之預防以及治療劑。
