In a comprehensive pooled‐data analysis, we have shown that higher PD‐L1 gene (CD274) expression is associated with improved survival, especially in basal‐like BC, whereas significant heterogeneity is noted when PD‐L1 protein expression is evaluated by immunohistochemistry (IHC) (Matikas et al., 2019b). This evidence concerns the gene CD274 and breast cancer.