This book discusses unique ion channels and transporters that are located within epithelial tissues of various organs including the kidney, intestine, pancreas and respiratory tract. The authors will show, that each of these channels and transporters play crucial roles in transepithelial ion and fluid transport across  epithelia and their responsibility in maintaining homeostasis. The reader gains an understanding of the fundamentals of epithelial ion transport, in terms of function, modelling, regulation, trafficking, structure and pharmacology. This is the third of three volumes highlighting the importance of epithelial ion channels and transporters in basic physiology and pathophysiology of human diseases.