SPRY4 and esophageal squamous cell carcinoma: Recent studies have shown that lncRNAs play pivotal roles in the initiation and progression of ESCC, for example, the lncRNA HOX transcript antisense RNA (HOTAIR) was reported to control cell cycle of ESCC [19]; the lncRNA HOTTIP promotes metastasis and the EMT progression of ESCC [20]; the lncRNA SPRY4-IT1 contributes to increased ESCC cells viability by activating zinc finger 703 expression [21] and so on.