The present invention relates to agents for use in treating cancer. The agent to be used is an antagonist of Dsg2, wherein the antagonist modulates the function of the amino acid sequence: TQDVFVGSVEELSAAHTLVMKINATDADEPNTLNSKISYR (SEQ ID NO:1), or a fragment or variant thereof, of the EC2 domain of Dsg2. Also included in the invention are specific polypeptides and pharmaceutical preparations. Also included in the invention is a method of screening for antagonists of Dsg2, wherein the antagonist modulates the function of the amino acid sequence: TQDVFVGSVEELSAAHTLVMKINATDADEPNTLNSKISYR (SEQ ID NO: 1), or a fragment or variant thereof, of the EC2 domain of Dsg2.