In order to examine whether the expression of SOX9 and aldehyde dehydrogenase 1 (ALDH1) proteins is associated with lymph node metastasis in HGOC, we used immunohistochemistry to analyze SOX9 and ALDH1 protein expression in 39 HGOC samples with or without lymph node metastasis (Figure 1a). This evidence concerns the gene ALDH1A1 and metastatic malignant neoplasm in the lymph nodes.