IFI6 and esophagus carcinoma in situ: To explore the clinical relevance of IFI6, we assessed the IFI6 abundance in non-cancerous esophageal tissues and in samples with progressively aggressive characteristics: esophageal hyperplasia, esophageal carcinoma in situ, low-grade ESCC, moderate-grade ESCC, and high-grade ESCC using IHC.