The present invention relates to a pharmaceutical composition for preventing or treating cancer, comprising an LRIT2 inhibitor as an active ingredient. The LRIT2 inhibitor according to the present invention can increase activity of immune cells, and thus can be used as an immunopotentiator. In addition, the LRIT2 inhibitor according to the present invention can potentiate immunity of an individual, and thus can be used to effectively prevent or treat cancer.本發明有關一種用於預防或治療癌症的藥學組成物,其包含LRIT2抑制劑作為活性成分。根據本發明之LRIT2抑制劑可增加免疫細胞的活性,因此可用作免疫增強劑。此外,根據本發明之LRIT2抑制劑可增強個體的免疫力,因此可用於有效地預防或治療癌症。