Tumor mutational burden (TMB) and programmed death 1 (PD-1) and its ligand (PD-L1) expression are two well-established biomarkers that are predictive of response to immune checkpoint inhibitor (ICI) therapy.1, , , , –6 These biomarkers have well-defined prognostic and predictive implications in solid tumors, but their prognostic role in hematologic malignancies is considerably less studied. The gene discussed is CD274; the disease is neoplasm.