According to the LASSO analysis (Figures 5A,B), nine paclitaxel resistance-specific key genes were obtained, namely, PHTF2, MFAP2, MME, INHBA, TSPAN9, MLLT11, CLDN1, KDELC1, and CCL26. Except for KDELC1 (not found in TCGA-ESCA), MLLT11, and TSPAN9, the expression levels of the paclitaxel resistance-specific key genes were significant in the ESCC tumor group compared with the normal group (padj. < 0.05) (Figure 5C). The gene discussed is CLDN1; the disease is esophageal squamous cell carcinoma.