The lymphatic system is composed of a hierarchy of vessels with specific features serving their unique functions: the blind-ended lymphatic capillaries that absorb the interstitial fluid and the collecting lymphatic vessels that transport the lymph to the cardiovascular system. Failure of the lymphatic vessels, caused by a genetic defect (primary) or damage following surgery or radiation therapy (secondary) can lead to lymphoedema, which is a progressive and lifelong condition characterised by gross swelling of the affected tissue. Notably, several primary lymphoedemas are characterised by defects that affect specific vessel types or organs. What underlies tissue-specific vessel failure is not understood yet this knowledge is instrumental in designing therapeutic strategies for lymphoedema and other lymphatic disorders that are currently lacking. In this project, we aim to identify genes that regulate organ-specific development and functional specialization of the lymphatic vasculature by characterising the features of specific vascular beds. Towards this aim, we will determine the molecular identity of functionally different types of lymphatic vessels by RNA sequencing of mouse lymphatic endothelial cells isolated from different organs in vivo, or human lymphatic endothelial cells exposed to different microenvironments in vitro.