The development of the “neuroendocrine concept” has sparked intensive research efforts that have led to fascinating insights into the complex and diverse system of neuroendocrine cells and their importance in human physiology and disease. Recent findings in developmental biology, regulation of angiogenesis, cellular signaling and transcription, and genomics and proteomics have warranted a reevaluation of the neuroendocrine concept. This volume provides a comprehensive update on neuroendocrine biology and pathobiology in these research areas. In particular, new discoveries are presented in neuroendocrine developmental biology, including transcription factors controlling neuroendocrine differentiation of endodermal stem cells.This volume also presents novel insights into the molecular mechanisms controlling formation and proliferation of blood and lymphatic vessels and molecular determinants of hematogenous and lymphatic tumor dissemination. Given their central importance for the establishment and maintenance of the neuroendocrine phenotype, signal transduction cascades and their cellular targets related to the regulation of adhesion processes, receptor-mediated endocytosis, and cell cycle events as well as secretory activation and membrane trafficking are discussed in the context of neuroendocrine physiology and neuroendocrine tumor disease. Many of the recent basic research discoveries can be directly linked to clinical applications, and this volume summarizes and discusses innovative treatment and/or diagnostic approaches for neuroendocrine tumor disease.