CD8A and neoplasm: Additionally, a decrease in circulating CD4+ and CD8+ T cells and an increase in Tregs and MDSCs were observed in the disease progression group, whereas the opposite changes in circulating immune cells were observed in the disease control group (109)In NSCLC patients undergoing nivolumab treatment, an elevated central memory/effector T-cell ratio was linked to better PFS, indicating higher tumor PD-L1 expression levels.