To determine the underlying mechanism of ENE, we analyzed the intracapsular (ENE-) (LN-in) and extracapsular (ENE+) (LN-out) metastatic lymph node samples from our cohort by comparing DEGs between malignant epithelial cells in these two groups and found that genes related to tumor invasion and metastasis (e.g., MT2A, SAA1, STATH, and CST1) were highly expressed in the LN-out group (Fig. 5A)9,31. Here, SAA1 is linked to neoplasm.