Next, to observe the target efficiency, we further transfected the plasmid p-T-miR-7 into six different human cancer cell lines, including lung cancer cell line 95D cells, A549 cells, NCI-H292 cells, gastric cancer cell line SGC901 cells, hepatitic cancer cell line HepG2 cells, and colon cancer cell line SW620 cells, and then detected the expression level of miR-7 operated by TTF-1 promoter. Here, TTF1 is linked to lung carcinoma.