NLRP1 expression level was higher in primary breast cancer tissue than in adjacent noncancerous tissue (p < 0.001) and NLRP1 expression was associated with lymph node metastasis (p = 0.003), TNM stage (p = 0.003), and Ki-67 levels (p < 0.001). Here, NLRP1 is linked to metastatic malignant neoplasm in the lymph nodes.