Perumal et al. used the CRISPR/Cas9 system to knock out the phosphatase and tensin homolog (PTEN) in the non-small cell lung cancer cell lines A549 and NCI-H460 by Nuclear translocation of β-catenin and Snail/Slug in lung cancer cells promotes EMT, which leads to metastasis (Perumal et al., 2019). The gene discussed is PTEN; the disease is lung carcinoma.