Our study demonstrates a new tumor-suppressor role of PD-L1 in repressing the proliferation and EMT-associated migration and invasion in aggressive EC cells, and reveals that the downregulation of MEG3 and induction of its downstream effector miR-216a is likely a novel mechanism underlying the downregulation of PD-L1 observed in EC tissues (Figure 7). Here, CD274 is linked to neoplasm.