CD274 and neoplasm: To elucidate how PDL1 expression is regulated in tumor-associated LECs, we treated immortalized mouse LECs (imLECs) with several (lymph-) angiogenic growth factors (VEGF-A, VEGF-C) and inflammatory cytokines (IFN-g, TNF-a), all of which are commonly expressed in the microenvironment of various tumors.