In multiple preclinical in vitro and in vivo models recombinant CPE has been shown to induce a dose-dependent eradication of claudin-3 and -4 tumor cells while the carboxy-terminal fragment of CPE (i.e., CPE290–319 binding peptide) has demonstrated promise as a carrier for tumor imaging agents and intracellular delivery of therapeutic drugs [41,151]. The gene discussed is CLDN3; the disease is neoplasm.