The present invention relates to a pharmaceutical composition and the like for treating and/or preventing cancer, said pharmaceutical composition containing the following as active ingredients: an MRAP2 protein comprising an amino acid sequence represented by SEQ ID NO. 2, 4, 6 or 8 or an amino acid sequence having at least 80% sequence identity with these amino acid sequences, or a fragment of said MRAP2 protein containing 7 or more continuous amino acids； and an antibody having immunological reactivity or a fragment thereof.
