GPX4 and neoplasm: In addition, as PD-1/PD-L1 interaction inhibits CD8+ T cell activity and enhances immune evasion in tumours [18], we hypothesized that via the PD-1/PD-L1 checkpoint OIP5-AS1/GPX4 could regulate CD8 + T cell alterations (p < 0.05, Figures 4(c) and 4(d)).