Therefore, we had to further study the impact of the two isoforms on EMT and cell invasiveness in lung cancer cells with different E-cadherin locations specifically by knocking down p120ctn isoform 1A in H460 and SPC cells with high p120ctn expression and transfecting cDNA plasmids for exogenous p120ctn isoforms 1A and 3A into H1299 and LK2 cells with low expression of p120ctn. The gene discussed is CDH1; the disease is lung cancer.