We found that DKK3 methylation was statistically correlated with clinical stage, lymph node metastasis and oestrogen receptor (ER) status (P < 0.05), but not associated with age, tumour size, progesterone receptor (PR) and hormone receptor (HR) status of breast cancer patients (Table 2). Here, DKK3 is linked to metastatic malignant neoplasm in the lymph nodes.