Preoperative treatment such as chemoradiotherapy and chemotherapy prior to total mesorectal excision is the current standard for locally advanced rectal cancer in many Western countries.11 Meanwhile, in Japan, upfront surgery (total mesorectal excision plus lateral lymph node (LN) dissection) without any preoperative therapy is performed as the standard treatment for rectal cancer.12 This unique strategy in Japan allows for serial evaluation of perioperative CEA levels in patients with rectal cancer, without any influence of preoperative therapy. The gene discussed is CEACAM5; the disease is rectal cancer.