Findings in GC, seem to be similar to those reported in lung cancer (Uruga et al. 2017; Takamori et al. 2017; Mansfield et al. 2016), whereas the concordance rate of PD-L1 expression was much higher comparing primary colorectal cancer and brain metastases based on the PD-L1 expression in only the tumour cells (≥ 1% of tumour cells with membranous staining was considered positive) (Roussille et al. 2018). Here, CD274 is linked to colorectal cancer.