Furthermore, the stability of BEX4 was directly regulated by PLK1-mediated phosphorylation, and it was highly correlated with the status of PLK1 expression in human lung cancer cell lines compared with non-tumor normal cell lines, including amniocyte and adipose-derived mesenchymal stem cells (AD-MSCs) (Fig. 5e). This evidence concerns the gene PLK1 and lung carcinoma.