PAK1 and metastatic malignant neoplasm in the lymph nodes: A gradual increase in PAK1 protein and mRNA levels in gastroesophageal tumor tissues was observed along the progression towards normal epithelium, atypical hyperplasia, and adenocarcinoma, and PAK1 overexpression was associated with lymph node metastasis, advanced tumor stage, large tumor size, positive surgical margins, and poor survival [29].