Epithelial cells are cells that come from surfaces of your body, such as your skin, blood vessels, urinary tract, or organs. They serve as a barrier between the inside and outside of your body and protect it from viruses. A small number of epithelial cells in your urine is normal.
----

The [[epithelial-mesenchymal transition]] (EMT) is a process by which [[epithelial cell]]s lose their cell polarity and cell-cell adhesion, and gain migratory and invasive properties to become [[mesenchymal stem cell]]s; these are [[multipotent]] [[stromal cell]]s that can differentiate into a variety of cell types.