Fig 2: Overexpression and downregulation of ubiquitin-specific protease 4 (USP4) influences the protein expression levels in the programmed cell death 4 (PDCD4) pathway. (A) The expression levels of PDCD4 target proteins [u-PAR, mitogen-activated protein kinase kinase kinase kinase 1 (MAP4K1) and c-Jun] were measured by western blot analysis in BT549 USP4-overexpressing cells and control cells. (B) The expression levels of PDCD4 target proteins (u-PAR, MAP4K1 and c-Jun) were measured by western blot analysis in MCF7 cells in which USP4 was silenced.

Fig 3: PLAU mediates the epithelial–immune interactome in HNSCC. a UMAP of immune cell populations in HNSCC. b Proportion plots of immune cell populations in HC and HNSCC. c Expression of PLAUR in UMAP of immune cell populations in HNSCC. d The relative gene expression levels of PLAUR in HNSCC clinical samples. n = 7 per group. e Immunofluorescence images of PLAUR (green) and CD68 (red, characterizing macrophages) in HNSCC clinical samples. n = 7 per group. Quantitative analysis of intensity is also shown. 20×, scale bar = 150 μm. Wilcoxon signed-rank test: *P < 0.05, **P < 0.01, and ***P < 0.001