Abstract: The disclosure provides a method for treating a subject afflicted with a tumor comprising administering to the subject a therapeutically effective amount of an anti-PD-1 antibody or antigen-binding portion thereof or an anti-PD-L1 antibody or anti-gen-binding portion thereof, wherein the subject is identified as having a high inflammatory gene signature score and a tumor that has a high tumor mutation burden (TMB) status. In some embodiments, the high inflammatory gene signature score is determined by measuring the expression of a panel of inflammatory genes in a tumor sample obtained from the subject, wherein the inflammatory gene panel comprises CD274 (PD-L1), CD8A, LAG3, and STAT1.