Introduction to cancer metastasis given, at one place, mainly all about the oral cancer. Overview about spending of cancer cells from primary tumor to secondary tumor. Different pathways of spreading cancer cells along with hallmarks of cancer, mechanism and molecular aspects of metastasis. Common sites of spreading cancer from oral cavity also discussed in this book.In addition, we illustrate the development of in vivo models and techniques for studying metastasis, methods for tumor development and metastasis spread, and immunotherapies that can potentially target cancer metastasis. All the points are deeply explained with clear photographs and schematic diagrams.