MEG3 and neoplasm: Given that MEG3 acts as a tumor suppressor to regulate EC progression by functioning as a competing endogenous RNA (Dong et al., 2019b), and that MEG3 contains the predicted miR-216a-binding site (Supplementary Figure 8B), we speculated that MEG3 might positively regulate the levels of PD-L1 by decreasing miR-216a expression in aggressive EC cells.