To investigate whether RECQL4 played a role in the biological behavior of ESCC cells, we first determined the mRNA and protein levels of RECQL4 in 5 ESCC cell lines, KYSE30, TE-1, KYSE150, KYSE450, and KYSE410, using qRT-PCR and Western blot assays. This evidence concerns the gene RECQL4 and esophageal squamous cell carcinoma.