Although there have been several reports on the prevalence of PD-L1 in GC, their sample size was generally small, and real-world data for advanced cases are rarely reported.32–35 In this study, tumor specimens from 389 Japanese patients with advanced gastric or GEJ adenocarcinoma were collected consecutively between 2014 and 2019 and evaluated. Here, CD274 is linked to gastroesophageal junction adenocarcinoma.