CLDN4 and metastatic malignant neoplasm in the lymph nodes: The present study showed that the number of E/M-CTC and M-CTC in the lymph node metastasis group was higher than that in the lymph node non-metastasis group and the numbers of CTCs in the high Claudin-4 group were higher than in the low expression level group, mainly due to the E/M- and M-CTCs since the E-CTCs were lower in the high Claudin-4 group.