MEG3 and lung carcinoma: Lung carcinoma cells were treated with si-LncRNA MEG3, miR-543-inhibition, and IDO signaling pathway inhibitor NLG919, and the cells were grouped into the si-LncRNA MEG3 + miR-543-inhibition + NLG919 IDO group, the si-LncRNA MEG3 + miR-543-inhibition group, the si-LncRNA MEG3 + NLG919 IDO group, and the NC group.