Serum p53 antibody titer has been proposed as a tumor marker for predicting advanced tumor stages and poor prognosis in ESCC preoperatively.21) Additionally, a post-therapeutic increase in serum p53 antibodies has been reported to be related to an unfavorable prognosis.22) Although the preoperative p53 antibody titer was negative in the current case, it increased after a 5-year disease-free period. The gene discussed is TP53; the disease is esophageal squamous cell carcinoma.