ESR1 and metastatic malignant neoplasm in the lymph nodes: However, there were no significant associations between estrogen receptor (ER) status (positive: negative), HER-2 receptor status (positive: negative), tumor size (≤ 1: > 1), and lymph node metastasis (N0+N1: N2+N3) and plasma NGAL level (all p > 0.05).