This book examines the relationship between the different infectious agents, such as viruses, bacteria, protozoa, and fungi, in the development of cancer. It is divided into six sections, spanning a range of topics, including infectious agents, main bacterial agents, and eukaryotic microorganisms, and how they contribute to cancer. Chapters also explore the anti-tumor effect of microorganisms, how pathogens induce epigenetic changes that are associated with cancer, and nutritional management for the prevention and treatment of pathogen-associated cancer, from a nutrigenomics perspective. The studies included cover epidemiological and immunological data, different OMICs data in general, and data of pathogens associated with cancer. The book is rounded out with an analysis of the role of glycans and molecular evolution in the progression of cancer.