PDCD1 and neoplasm: Liu et al. (2022) observed an increment in precursor exhausted T cells, defined as CXCL13+ TIM3- CD8+, in tumor samples from patients with NSCLC who responded to anti-PD1 treatment, in contrast to tumors that did not respond to PD1 treatment and had an accumulated proportion of terminally exhausted CD8+ T cells [53].