Through the intersection of differentially expressed genes (DEGs) that are highly expressed in gastric cancer tissues with those DEGs highly expressed in early-stage (T1) gastric cancer tissues exhibiting LNM, and with prognostic genes, we identified two biomarkers: HAVCR1 and Claudin 6 (CLDN6) (Figure 3A). The gene discussed is CLDN6; the disease is gastric cancer.