CD274 and leukemia: To prove that A20 leukemia cells behave just like other transplantable syngeneic tumor models, the PD-L1 WT and its counterpart PD-L1-deficient A20 tumor cells were exposed in vitro to IFN-γ (200 ng/ml for 24 h) or left untreated to determine whether PD-L1 expression was modulated in response to this cytokine.