The biomarkers of ESCC tissues, such as ACTA2, TAGLN, POSTN, PSAP, and THBS120,21, were also detected and significantly increased during ESCC progression (Kruskal–Wallis test, FDR < 2.2E–16, stage 9 vs. stage 1 ratio ≥ 2) (Supplementary Fig. 5e, f). The gene discussed is PSAP; the disease is esophageal squamous cell carcinoma.