With regard to oesophageal cancer patients, some papers reported that high PD-L2 expression in oesophageal cancer was associated with impaired survival,18,19 and another study showed no correlation between PD-L2 and clinical outcome.20 However, all of these studies were limited by small sample sizes (n ≤ 180) and low statistical power. The gene discussed is PDCD1LG2; the disease is carcinoma of esophagus.