ALDH1A3 and metastatic malignant neoplasm in the lymph nodes: We assessed the methylation patterns of four genes across various clinical subgroups and observed that patients in stage IV exhibited significantly reduced methylation of genes ALDH1A3 and TMEM163 compared to those in stages I−II, while patients with lymph node metastasis showed a decrease in methylation of CTXN1, MGAT3, and TMEM163 (Figures 8D–G), suggesting that the hypomethylation-induced transcriptional activation of these genes may contribute to tumor metastasis and the progression to advanced stages.