The present disclosure provides a pharmaceutical composition for treating or preventing cancer, comprising inhibitors of KIRREL3, CNTN4 and/or CD351. In addition, the present disclosure provides a pharmaceutical composition for immune-enhancing, comprising inhibitors of KIRREL3, CNTN4 and/or CD351. Furthermore, the present disclosure provides a method of screening of anti-cancer agent using KIRREL3, CNTN4 and/or CD351, and a method of providing information necessary for analysis of cancer prognosis using KIRREL3, CNTN4 and/or CD351.本發明提供一種用於治療或預防癌症的醫藥組合物,其包含KIRREL3、CNTN4、及/或CD351之抑制劑。此外,本發明提供一種用於增強免疫的醫藥組合物,其包含KIRREL3、CNTN4、及/或CD351之抑制劑。此外,本發明提供一種利用KIRREL3、CNTN4、及/或CD351篩選抗癌劑的方法,以及一種提供利用KIRREL3、CNTN4、及/或CD351分析癌症預後所需資訊的方法。