PDCD1 and neoplasm: In this study, we present an antigen-agnostic method to identify tumor-specific T-cell clonotypes based on (1) numerical dominance among TILs, (2) high tumor-to-non-tumor frequency ratios, (3) PD-1 expression, and (4) verification of clonotype selection by single-cell gene expression data showing that candidate clonotypes express gene signatures indicative of chronic activation, terminal differentiation and/or exhaustion.