Among the 9 exons of FAM134B (JK1) examined, mutations were detected in exons 4, 5, 7 and 9 as well as introns 2, 4, 5, 6, 7 and 8 for FAM134B (JK1) in ESCC (Figs 2 and 3). This evidence concerns the gene RETREG1 and esophageal squamous cell carcinoma.