SPRY4 and esophageal squamous cell carcinoma: In the first experiment, qPCR was used to measure the POU3F3, HNF1A-AS1 and SPRY4-IT1 expression in different five esophageal cell lines (including four ESCC cells: KYSE30, KYSE70, KYSE450, and Eca 109, and one normal human esophageal epithelial cell line: HET-1A), and each cell culture medium which was incubated for 1, 2, and 3d (Figure 5A and B).