IL6 and esophageal squamous cell carcinoma: Although our data did not detect IL-6 directly, pathway enrichment analysis revealed that the interleukin signaling pathway was activated, and levels of related molecules were significantly increased in ESCC serum, including CA1, CFL1, UBE2V1, VIM and YWHAZ, which mediate the expression of IL-3, IL-4, IL-5, IL-12 and IL-13.