PIK3CA and cancer: Moreover, the KEGG pathway enrichment analysis showed that the upregulated differentially regulated genes were predominantly enriched in pathways such as Natural killer cell mediated cytotoxicity, T cell receptor signaling pathway, and Cytokine-cytokine receptor interaction, while the downregulated genes were mainly enriched in pathways including PD-L1 expression and PD-1 checkpoint pathway in cancer, PI3K-Akt signaling, and mTOR signaling pathway (Fig. S8I, K).