Correlation analysis of DDAH1 expression with patients’ clinicopathological characteristics (Table 2) demonstrated that DDAH1 expression was negatively associated with the presence of lymph node metastasis (P = 0.034) and diffuse classification (P = 0.013), but positively with differentiation status (P = 0.003, Fig. 1D). Here, DDAH1 is linked to metastatic malignant neoplasm in the lymph nodes.