Although the deleterious mutant RAD50L1264F did not associate with higher familial ESCC risk, our functional study suggested patients carrying this East-Asian-specific heterozygous RAD50L1264F (Table S1) may have a dominant negative effect upon induction of replication stress by formaldehyde treatment and the CHK1 inhibitor, AZD7762. The gene discussed is CHEK1; the disease is esophageal squamous cell carcinoma.