CTC play a central role in tumor dissemination and metastasis, and have been established as an important evaluative and research tool in advanced cancer, and potentially important in early stage disease. CTC defines tumor cells circulating in blood, while Disseminated Tumor Cells (DTC) refers to tumor cells identified in bone marrow. CTC/DTC are extremely rare events, even in late stage cancer, and their detection has presented enormous technical challenges, with the emergence of multiple technologies developed to address these challenges, including enrichment, identification and sophisticated analytical techniques to evaluate CTC and other cells in circulation that may also be important in the biology of metastasis. This second edition of is entirely new and brings together leaders and innovators in the field of liquid biopsy, including basic and molecular biologists, chemists, engineers, statisticians, experts in tumor banking, test developers, research administrators and clinicians. A special feature of this book is that it includes chapters from the members of the US National Cancer Institute Liquid Biopsy Consortium. This edition also includes many of the participants of the latest international meeting on the (ACTC) which is held in Greece every two years and gathers the most important liquid biopsy investigators from around the world. Thus, this edition represents the most comprehensive and up-to-date resource for those who want to further explore the exciting field of CTC and other liquid biopsy technologies. The new edition will be useful to a wide audience including scientists studying metastasis, cancer researchers, translational scientists, oncologic surgeons, medical oncologists, members of the biopharmaceutical industry, and graduate and undergraduate students studying cancer biology.