For example, 5-ALA induces ferroptosis via regulation of GPX4 and heme oxygenase 1 (HMOX1) and exerts antitumor effects in esophageal squamous cell carcinoma cell lines and BALB/cAJcl-nu/nu mice with subcutaneously transplanted KYSE30 cells [161]. This evidence concerns the gene GPX4 and esophageal squamous cell carcinoma.