S100A9 and esophageal squamous cell carcinoma: Among these DEGs, MT2A may serve as a promising favorable prognostic indicator in ESCC patients undergoing neoadjuvant anti-PD-1 combined therapy, whereas C3AR1 [65], FCER1G, APPL1 [66], S100A8 [71], S100A9, CXCL1 [72], and ITGB2 [73] might be associated with an unfavorable prognosis in ESCC.