Figure 2. (A) Volcano plot of the differential expression of 270 GRTTKs between tumor and normal samples in the TCGA-ESCC cohort. (B) Univariate Cox regression analysis of 35 GRTTKs and prognosis in ESCC. (C) Heatmap displayed displaying the differential expression of 35 GRTTKs between tumor and normal samples. (D) Boxplots of the differential expression of 35 GRTTKs between tumor and normal samples. (E) Copy number variation (CNV) of 35 GRTTKs in ESCC.