CXCR4 and metastatic malignant neoplasm in the lymph nodes: In the ROC curve, we found that the diagnostic efficiency of CXCR4 alone is lower than that of MRI alone, but MRI combined with CXCR4 has the highest efficiency in diagnosing head and neck lymph node metastasis, which provides a new idea for the clinical diagnosis of HNSCC lymph node metastasis.