RAD50 and esophageal squamous cell carcinoma: While the significance of the two zinc hook pathogenic mutations of RAD50 based on their incidence do not justify their use in generalized screening due to their rarity in the population-at-large observed in the current study with 4 patients out of 1044 familial ESCC cohort and the publicly available reported incidence of 4 out of 19,945 East Asian noncancer individuals; however, they are clinically important.