CD8A and non-small cell lung carcinoma: In NSCLC, dominant TCR expansion was observed not only within the tumor tissue but also in circulating T cells, and early and sustained TCR clonal expansions in the blood were present in ICI responders [56,59] Recently, Han et al. reported that pretreatment PD-1+ CD8+ TCR diversity in the peripheral blood was higher in patients with disease control than in those with disease progression, and high PD-1+ CD8+ TCR diversity (>3.14) was associated with better response, longer PFS, and OS in NSCLC patients treated with PD-(L)1 inhibitors [39].