Fig. 2

The architecture of CASC9 and its expression in ESCC specimens. a The genome architecture of CASC9 coding region. b qPCR analysis of CASC9 expression in 87 ESCC tissues and paired normal tissues. The results were expressed as log2 (2^-∆∆Ct). Overexpression of CASC9 was detected in 90.8% (79/87) of ESCC tissues. c and d qPCR analysis of CASC9 expression in 91 ESCC tissues at different pathological stages and 87 paired normal tissues. CASC9 expression was significantly higher in patients at advanced pathological stages; one-way ANOVA analysis was performed to calculate the statistical difference. CASC9 expression was significantly higher in samples with larger tumor size. The statistical differences between the two groups were analyzed using unpaired Student’s t-test. e Survival analysis based on CASC9 expression levels in 69 cases of ESCC patients. The median level of CASC9 was used as cutoff. ESCC patients were divided into CASC9 high expression group and low expression group. The survival time of ESCC patients was compared between groups using the Log-Rank test, which indicated poor prognosis of patients in the high CASC9 expression group (P < 0.01). *** P < 0.001