E-cadherin, widely expressed in epithelial cell types, plays an important role in cell-cell adhesion in epithelial tissues. Here I characterize a transgenic mouse strain in which EGFP expression is driven from the E-cadherin gene to evaluate its use as a tool. EGFP expression was analyzed in the stromal epithelium of the thymus made up of thymic epithelial cells-TECs. Our results show that high levels of EGFP expression in the thymus is detected exclusively in medullary TECs and correlates with a subset of thymic epithelial cells in the medulla where E-cadherin is expressed highest. We have characterized EGFP expression in other epithelial tissues and have concluded that EGFP expression recapitulates CDH1 expression. We therefore propose that this mouse model can be used as a marker for a subset of medullary TECs allowing them to be distinguished from the rest of the population as well as for epithelial cells in other organs.