CASC9 and esophageal squamous cell carcinoma: We identified Gal-1 directly binds to ESCCAL-1 in ESCC cells using RNA-protein pull-down, RIP, and immunofluorescence co-location assays, to our knowledge, it is the first time to report that Gal-1 can act as an RNA-binding protein in tumor cells, the detailed protein binding motif in ESCCLA-1 remain further characterized in the future study.