The expression of PPA1 is significantly increased in the metastatic lymph nodes of malignancies, including gastric cancer (8, 40), colorectal cancer (14), ovarian cancer (16), and laryngeal squamous cell carcinoma (LSCC) (41) as assessed by immunohistochemistry or tissue microarrays, compared to that in controls. Here, PPA1 is linked to ovarian cancer.