Next, XWLC-05, YTMLC-90, and NCI-H157 cells were transiently transfected with the pGCMV/EGFP-hsa-miR-34a or pGCMV/EGFP-hsa-miR-NC plasmid using Lipofectamine 2000 to further demonstrate whether miR-34a functions as a tumor suppressor in lung cancer in Gejiu and Xuanwei County based on the previous finding that miR-34a has been shown to possess tumor-suppressive functions in NSCLC cell lines such as A549 (p53 wild-type), H460 (p53 wild-type), and H1299 (p53 mutant) (48). The gene discussed is TP53; the disease is lung cancer.