S100A8/S100A9 expression could be detected in 74.4% of lung SCCs, 100% of esophageal SCCs, 100% of cervical SCCs, 96% of oral SCCs, and 95% of skin SCCs stained positive for both S100A8/S100A9 (Additional file 1: Table S3). Here, S100A9 is linked to esophageal squamous cell carcinoma.