SOX2 and lung cancer: The previous study has verified that SOX2 gene overexpression inhibited cisplatin‐induced cell apoptosis in lung cancer cells, while SOX2 knockdown led to an enhanced susceptibility of A549 and A549/DDP cells to cisplatin along with increased cell apoptosis (He et al., 2017), which suggested that SOX2 may be an important regulator in chemoresistance of cisplatin in lung cancer cells.