TP53 and esophageal squamous cell carcinoma: And the mutation frequency of TP53 in our GEJ cancer patients was 50%, much lower than that in EC [71% in EAC and 91% in ESCC (esophagus squamous cell carcinoma)], but close to that in GC (50% in non-hypermutated gastric cancer and 35% in hypermutated gastric cancer).