Bai et al. found that high expression of the CXCR4 protein was more common in mixed CTCs, which may be associated with CTCs progression and metastasis.117 And the Guidelines for the Diagnosis and Treatment of Primary Liver Cancer in China suggest that CTCs testing can serve as a novel clinical tool for predicting prognosis and evaluating the effectiveness of treatment for liver cancer. This evidence concerns the gene CXCR4 and liver cancer.