BMP4 and esophageal squamous cell carcinoma: To understand the regulatory mechanism of these immune differential genes related to prognosis, we developed a regulatory network of TF-immune gene interaction based on these differential TFs and our previously screened immune differential genes, finding that BMP4, CD14, PSME2, HLA-B, IGF2, CKLF, FABP9, IL1F10, TSLP, and OSM were high-risk immune genes while NR2F2, EGFR, and BMP1 were low-risk immune genes in ESCC (Figure 4A).