Fig. 1

NCSTN is highly upregulated in hepatocellular carcinoma. a Meta-analysis of NCSTN, APH-1, PEN-2 and PS-1 in hepatocellular carcinoma based on the Oncomine database (http://www.oncomine.org). Nine databases comparing hepatocellular carcinoma tissues with corresponding normal tissues were used. The colour of the square represents the different levels of NCSTN expression. Red indicates overexpression in hepatocellular carcinoma, while blue indicates low expression. b Boxplot for NCSTN, APH-1, PEN-2 and PS-1 expression in HCC. The red and grey boxes represent liver tumour and normal tissues, respectively. The y-axis indicates the log2-transformed gene expression level. The data were obtained from TCGA through GEPIA (http://gepia.cancer-pku.cn). c High NCSTN expression in HCC indicated a poor prognosis. Overall survival and disease-free survival of HCC patients with high or low NCSTN expression in TCGA determined by GEPIA. Kaplan–Meier plots for NCSTN, APH-1, PEN-2 and PS-1 were generated by Kaplan–Meier Plotter (http://www.kmplot.com). d A visual summary displaying the genetic alteration of γ-secretase compounds in TCGA-LIHC patients, retrieved from the CBioPortal database (https://www.cbioportal.org)