Research Article Nikola Cousin, Stefan Cap, Manuel Dihr, Carlotta Tacconi, Michael Detmar and Lothar C. Dieterich DOI: 10.1158/0008-5472.CAN-21-0633 Abstract Lymph node (LN)-resident lymphatic endothelial cells (LEC) mediate peripheral tolerance by self-antigen presentation on MHC-I and constitutive expression of T cell inhibitory molecules, including PD-L1. Tumor-associated LECs also upregulate PD-L1, but the specific role of lymphatic PD-L1 in tumor immunity is not well understood.