The lymphatic system is an essential part of the immune system. It serves distinct yet complementary functions with the blood vascular system in maintaining tissue homeostasis, including interstitial protein transport, tissue fluid balance, pressure equilibrium, and development of cellular immunity. Although lymphatic capillary endothelial cells have many properties in common with the endothelium of blood vessels, they possess distinct structural characteristics reflecting specific functions. Lymphatic capillaries firmly integrate within the interstitium, which is connected to the extracellular matrix by fine strands of elastic fibers. These capillaries have absent or poorly developed basement membranes and lack surrounding mural cells. Lymphatic endothelium typically contains numerous invaginations and cytoplasmic vesicles, as well as, characteristic overlapping intercellular junctions. Lymphatic endothelial cells are important modifiers of tumor microenvironment and are implicated in metastasis. HDLEC from ScienCell Research Laboratories are isolated from human skin. HDLEC are cryopreserved at passage one and delivered frozen. Each vial contains >5 x 105 cells in 1 ml volume. HDLEC are characterized by immunofluorescence with antibodies specific to vWF, podoplanin and/or Lyve1. HDLEC are negative for HIV-1, HBV, HCV, mycoplasma, bacteria, yeast, and fungi. HDLEC are guaranteed to further expand for 15 population doublings under the conditions provided by ScienCell Research Laboratories. Recommended Medium It is recommended to use Endothelial Cell Medium (ECM, Cat. #1001) for culturing HDLEC in vitro.