This text covers the complex structure of cells and how they signal to each other when the body is infected with cancer. Head and neck cancer is covered in detail to illustrate a cancer in humans where these considerations are particularly relevant. This volume demonstrates that the principal factor in cancer patient immunologic defiency is related to excess secretion of monocytes of prostaglandins. The text explains how a cancer patient’s immunologic defiency may be largely related to abnormalities of monocyte eicosanoid metabolism, and provides successful methods and approaches to augment anti-tumour immunity in cancer patients by inhibiting various pathways in eicosanoid metabolism.