The identification of HER2/neu and CPE epithelial receptors among others as some of the most highly differentially expressed genes in USPC when compared to NEC suggest that therapeutic strategies targeting HER2/neu by monoclonal antibodies (Villella et al, 2003) and claudin-3 and claudin-4 by local and/or systemic administration of CPE (Long et al, 2001; Michl et al, 2001) may represent novel potentially effective modalities for the treatment of patients harbouring this highly aggressive and chemotherapy-resistant variant of endometrial cancer. This evidence concerns the gene CLDN3 and endometrial cancer.