Median PD-L1 surface expression was higher on patients' ALL blasts at relapse (median PD-L1 expression: 9.5%; n=11) as compared to patients with primary diagnosis (median PD-L1 expression: 1.1%; n=8) and to controls (median PD-L1 expression: 0.49%, n=6) (Figure 2D). The gene discussed is CD274; the disease is acute lymphoblastic leukemia.