CD274 and neoplasm: Several studies regarding other tumour types found the same results, suggesting a more complex function of PD‐L1 in immunosurveillance signalling.67 A possible explanation is that PD‐L1 expression by cancer cells can be considered as a marker of an active host anti‐tumour immune response.68 Another way to address the issue is to consider the heterogeneity of tumour microenvironment in different tumour types.