We then established stable RECQL4-knockdown ESCC cell lines (KYSE30 and TE-1) and RECQL4-overexpression ESCC cell lines (KYSE150 and KYSE410) and analyzed cell proliferation, cell cycle distribution, the levels of DNA damage and reactive oxygen species, cell migration, and invasion. This evidence concerns the gene RECQL4 and esophageal squamous cell carcinoma.