Disclosed is an anticancer composition, comprising an inhibitor against WIG1 and/or YPEL5 or against a protein encoded by the gene. A composition for screening an anticancer agent comprising a nucleic acid having a sequence complementary to an mRNA of WIG1 and/or YPEL5, or an antibody to a protein encoded by the gene is also provided. Also, a method is provided for screening an anticancer agent, which comprises: (A) quantitatively analyzing expression of WIG1 and/or YPEL5 at an mRNA or protein level in a tumor cell which is not treated with a candidate for an anticancer agent (B) quantitatively analyzing expression of the gene at an mRNA or protein level in a tumor cell after treatment of the candidate for an anticancer agent and (C) selecting the candidate if the expression level of the gene is increased in step (B), compared to step (A).
