Squamous epithelia form the lining surface of tissues in contact with the environment: the skin, oral mucosa, esophagus and respiratory tract, the genital tract, and several other specialized tissues. These tissues are at highest risk for exposure to environmental carcinogens such as UV, tobacco smoke and infectious agents. Cancers that form in squamous epithelia are among the most common human solid tumors and have high morbidity and mortality. These cancers include squamous cell carcinoma of the skin, oral cancer, head and neck and esophageal cancer, certain lung cancers and cervical cancer. We propose to organize the book so that the early chapters will focus on individual pathways and more specific mechanisms in both normal function and cancer, while the later chapters will be more integrative and include overviews of biomarkers and therapeutic development. This should increase interest for clinically oriented researchers. All authors will be encouraged to provide a balanced review in addition to highlighting their own work.