Cancers are tumors of epithelial tissues and are malignant.
"Special Report on Diseases of Cattle"
U.S. Department of Agriculture J.R. Mohler
All the cells of a living organism are extremely sensitive to slight differences of osmotic pressure-the cells of epithelial tissue and of the nervous system as well as the blood cells.
"The Mechanism of Life"
Stéphane Leduc
The fetal and maternal placentas are made up of vascular villi and depressions that are separated only by the thin walls of capillaries, and a layer of epithelial cells.
"Common Diseases of Farm Animals"
R. A. Craig, D. V. M.