The pathway enrichment analysis showed that these differentially expressed genes were enriched in the signaling pathways including PI3K-Akt signaling pathway, NF-kappa B signaling pathway, two-component system, pathways in cancer, transcriptional dysregulation in cancer, microRNAs in cancer and EMT indicating that EP300 may contribute to ESCC tumorigenesis via these pathways (Figure 5A). This evidence concerns the gene PIK3CA and cancer.