CASC9 and esophageal squamous cell carcinoma: The intersection of 643 lncRNAs in the ESCC ceRNA network and the differentially expressed lncRNAs in GSE120356 screened 10 important lncRNAs, namely CASC9, SOX21-AS1, HCP5, HCG22, RNF217-AS1, CALML3-AS1, LINC00491, BBOX1-AS1, C5orf66, ZFPM2-AS1, shown in Fig. 4A.