Development and structure of the lymphoid system

The lymphatic system is a complex, blind-ended vascular system separate from the blood circulatory system that plays key roles in fluid homeostasis, immune surveillance, and cancer progression. Recent discoveries in lymphatic biology have greatly advanced our understanding of the lymphatic vasculature and its roles in various pathophysiological conditions. The identification of specialized lymphatic beds has also revealed the remarkable plasticity of lymphatic endothelial cells and their ability to acquire distinct tissue-specific functions. In this chapter we provide an overview of fundamental mechanisms governing lymphatic vessel development and their specialized functions in different organs. We also review the highlights of recent findings regarding the role of the lymphatic system in immunity and cancer.