Building upon prior bioinformatic findings linking PLK1 expression to tumor staging and immune infiltration patterns (B lymphocytes, CD4+ T cells, macrophage populations) (Li et al., 2021), our comprehensive analysis reveals PLK1-overexpressing LUAD specimens demonstrate an immunosuppressive microenvironment characterized by elevated regulatory T cells (Tregs) and Th2 polarization, concurrent with diminished infiltration of immature dendritic cells (iDCs), conventional dendritic cells (cDCs), and cytotoxic CD8+ T lymphocytes (Fig. 6). This evidence concerns the gene CD4 and neoplasm.