Because EpCAM-deficient placentas were smaller and the labyrinthine layers were thinner and less elaborate than in controls, impaired placental development in this setting may reflect a more global effect on epithelial cell physiology. EpCAM is expressed by embryonic stem cells and cancer stem cells, and it is possible that EpCAM influences trophoblast stem cell behavior. In future studies, it will be of interest to explore other potential roles of EpCAM in vivo. These studies will require generation of mice that carry EpCAM alleles that can be targeted in selected lineages and/or at selected times. The importance of elucidating EpCAM function in vivo is highlighted by recent studies that demonstrate that at least some cases of congenital tufting enteropathy, a rare, typically autosomal recessive syndrome that is Rebamipide characterized by intractable infantile diarrhea, result from mutations in the gene encoding EpCAM. Intrauterine demise or abnormal fertility has not been reported in families of patients with congenital tufting enteropathy, but it may be significant that null mutations in the gene encoding EpCAM, or mutations that resulted in truncated EpCAM protein, have not yet been identified in patients. The mutations identified to date may be hypomorphs that result in identifiable abnormalities in some EpCAMexpressing epithelia, but not others. The availability of conditional knockout mice and transgenic mice that express candidate hypomorphic EpCAM alleles will allow EpCAM function to be additionally explored in embryonic development, reproduction, and adult physiology. Recent experiments in Perphenazine zebrafish implicate EpCAM in epithelial morphogenesis during epiboly and skin development, suggesting that future studies of conditional EpCAM knockout mice will be informative. Atopic dermatitis is a chronic inflammatory skin disease that is increasingly more common in infants and children. The clinical symptoms of AD are characterized by elevated serum immunoglobulin E levels and pruritic and relapsing eczematous skin lesions, which are distinguished by epidermal thickening; defective skin barriers; and infiltration of inflammatory cells, such as lymphocytes, macrophages, eosinophils, and mast cells. T-helper 2 cells producing thymus and activation-regulated chemokine, interleukin -4, IL-5, and IL-13 play major roles in AD onset and development.