This book, now in a thoroughly revised and updated second edition, provides the latest information on cancer metastasis from the perspective of inflammation and presents new ideas on the complicated mechanisms of metastasis and potential therapeutic targets. Key features include discussion of mechanisms recently identified to be involved in the resolution phase of inflammation, presentation of the latest evidence regarding the roles of endogenous TLR4 ligands in metastasis, and thorough explanation of the concept of homeostatic inflammation and current understanding of the significance of its dysregulation for metastasis. Structure-based thinking is another important element of the book, and it is proposed that inflammation forms a functional triangle with angiogenesis and coagulation, at the center of which cancer is located. Examples of the many additional specific topics covered in this edition include the functional involvement of new types of RNA in cancer, the insights offered by recent advances in bioinformatics, and the potential of a casein kinase 1 inhibitor in the treatment of acute myeloid leukemia. The book will be a valuable update and resource for both experienced and younger researchers. Homeostasis, originated from an idea of internal milieu by Claude Bernard, is eventually maintained by endogenous elements. The essential features of inflammation are leukocyte mobilization and increased vascular permeability, which could take place in many homeostatic or physiological conditions at low levels. Homeostatic inflammation is a concept to explain pathological settings such as metastasis in which irrespective of its level those inflammatory features are misused with endogenous molecules (see Chap. 14,15). As inflammation comprises many biological fields, targeting a single molecule for a disease could potentially make a therapeutic contribution to other diseases. For example, one focus is applied here to the roles of calprotectin in lung metastasis, which is implicated in psychiatric disorders and COVID-19 as shown by recent evidence.