RAD51 and cancer: One predictive factor for chemoradiotherapy response in a variety of human cancers is Rad51.10,11 Rad51 is a key factor in homologous recombination.12 Overexpression of Rad51 decreases radiation sensitivity and confers resistance to DNA cross-linking agents such as cisplatin.13,14 We therefore hypothesized that Rad51 expression would predict the response to NACRT in ESCC.