To elucidate the oncogenic role of ESCCAL-1 in sustaining ESCC cell proliferation, we ectopically expressed ESCCAL-1 in a KYSE150 ESCC cell line, which the ESCCAL-1 expression is relative lower, and silenced ESCCAL-1 expression in EC9706 and KYSE450 ESCC cell lines with higher ESCCAL-1 expression, and performed CCK-8 experiment, colony formation assay, and EdU staining. This evidence concerns the gene CASC9 and esophageal squamous cell carcinoma.