The expression levels of AREG, BIRC3, DKK1, EREG, FOSL1, MYC, and PLAU are negatively correlated with the survival ratio, and are significantly higher in the TSPX-low lung adenocarcinoma samples, compared to TSPX-high lung adenocarcinoma samples (Figure 5). This evidence concerns the gene DKK1 and lung adenocarcinoma.