In this study, we genotyped six SNPs in ER stress–related genes EIF2AK3/PERK, HSPA5/GRP78, and DDIT3/CHOP in lung cancer patients and healthy individuals and found that EIF2AK3-rs6750998 was a protective mutation against the risk of lung cancer, and three SNPs (EIF2AK3-rs867529, HSPA5-rs391957, and DDIT3-rs697221) were risk factors for the disease. Here, DDIT3 is linked to lung cancer.