Fig. 1

IFI6 expression is elevated in ESCC and predicts a poor prognosis. a. IFI6 expression levels in ESCC tissues vs. non-tumorous tissues (NTs) were analyzed using the GEO database (GEO accession no. GSE20347, no. GSE23400, no. GSE45670 and no. GSE75241). The data were normalized to IFI6 expression in NTs and are presented as the means and SDs. Statistical significance was determined by a modified t-test (implemented via the limma package in R). ***P < 0.005. b. Relative IFI6 mRNA levels in 23 ESCC tissues and paired adjacent non-tumorous tissues (PANTs) were measured via RT-PCR. The data were normalized to IFI6 expression in PANTs and are presented as the means and SDs (n = 3). Statistical significance was determined by a two-tailed Student’s t-test. **P < 0.01. c. IFI6 mRNA levels in the esophageal squamous epithelial cell line Het-1a as well as a panel of ESCC cell lines. The data were normalized to IFI6 expression in Het-1a cells and are presented as the means and SDs (n = 3). Statistical significance was determined by two-tailed Student’s t-test. **P < 0.01, ***P < 0.005. d. Representative Western blot showing the protein abundance of IFI6 in the esophageal squamous epithelial cell line Het-1a as well as a panel of ESCC cell lines. GAPDH was used as the loading control. e. Representative immunohistochemical images in the healthy human esophageal epidermis, esophageal hyperplasia and ESCC tissues at increasing disease stages; P1-P12 indicate the donor number. Magnification: 40×, Scale bar: 50 μm. f. Plots visualizing the Kaplan-Meier plot and log-rank-trend-test for ESCC patients from 83 cases of IHC cohort separated into groups of high, medium and low IFI6 expression levels. Statistical significance was determined via the log-rank test and log-rank trend test