CD8A and non-small cell lung carcinoma: The scientific importance is highlighted by unveiling the critical role of the PI3K/Akt/mTOR signaling pathway in PIK3CA-mutant NSCLC and providing a novel peptide, TSRP, that enhances CD8+ T cell infiltration and suppresses PD-L1 expression by downregulating this pathway, reshaping the tumor immune microenvironment.