KRAS and breast cancer: Previous studies have shown that six2 is required for DDX3‐mediated tumour aggressiveness and cetuximab resistance in KRAS‐wild‐type colorectal cancer,22 has been confirmed to facilitate breast cancer metastasis.10 Recent study has demonstrated that six2 is negatively correlated with good prognosis and decreases 5‐FU sensitivity in hepatocellular carcinoma cells via regulating cell stemness.23 However, the roles and related mechanism in NSCLC progression are still unclear.