To date, several small molecule inhibitors targeting cell cycle checkpoints have been developed for clinical applications, including PLK1 inhibitors, Aurora kinase inhibitors, and CDK inhibitors.[4, 5, 6] Although an increasing number of clinical trials have shown that cell cycle checkpoint inhibitors could be an effective treatment option for relapsed or refractory cancer patients,[7, 8] the clinical utilization of these inhibitors has been hindered due to limited successes in CRC. This evidence concerns the gene PLK1 and cancer.