This book is devoted to vascular endothelial growth factor A (VEGF or VEGFA), a secreted signalling protein of great significance for development and disease in vertebrates. VEGFA controls the proliferation, migration, specialisation and survival of vascular endothelial cells, and it is therefore essential for the establishment of a functional blood vessel circuit. In addition, VEGFA is emerging as a versatile patterning factor for several non-endothelial cell types in vertebrates. Thus, it plays a central role during organ development at multiple levels, including blood vessel growth, vessel-mediated organ induction and tissue differentiation.In writing this book, scientists investigating different aspects of VEGF signalling have come together to highlight the central importance of this growth factor for vertebrate development. From their reviews of our present knowledge, it becomes clear that VEGF's versatility as a patterning molecule is linked to its expression as several splice forms that interact with a number of differentially expressed signalling receptors. Moreover, by highlighting the present gaps in our knowledge, the authors of this book set direction to future research. It is therefore hoped that this book will provide valuable insights to those already studying VEGF as well as to those members of the scientific and medical community that seek to understand vertebrate development and the origins of disease without specific prior knowledge of the field.