PD-L1 expression is indeed dynamic and variable, and this depends on many different factors, both tumor-dependent (heterogeneity of PD-L1 expression within and between tumor lesions, PD-L1 expression by various cell types in the tumor microenvironment) and immunohistochemistry assays-dependent (different antibodies used to detect PD-L1, variable cut-offs to define a PD-L1 test result as positive) [86,87]. Here, CD274 is linked to neoplasm.