A prognostic analysis using 69 ESCC tissues with complete follow-up information revealed that both high CASC9 expression in ESCC tissues and high T:N ratio were associated with reduced overall survival (Fig. 1f, g), while no significant association between CASC9 expression in normal tissues and survival was detected (Fig. 1h). This evidence concerns the gene CASC9 and esophageal squamous cell carcinoma.