Fig 2: High CK2α expression is associated with an immunosuppressive tumor microenvironment, T-cell exhaustion, and poor clinical outcomes in non-small cell lung cancer. A Schematic overview of patient enrollment and cohort stratification. A total of 104 patients with resectable non-small cell lung cancer (NSCLC) were included in the final analysis (n = 104). B Representative immunohistochemical (IHC) staining of CK2α in lung cancer tissues demonstrating graded expression intensity (0, negative; 1+, weak; 2+, moderate; 3+, strong), together with representative IHC images of immune markers (CD3, CD4, CD8, CD68, PD-1, and PD-L1). Scale bar, 50 μm. Representative images from one patient per group are shown. C Kaplan–Meier analysis of disease-free survival (DFS) and overall survival (OS) in patients undergoing curative resection, stratified by CK2α expression status (low CK2α, n = 14; high CK2α, n = 90). Survival differences were evaluated using the log-rank (Mantel–Cox) test. D Quantification of total tumor-infiltrating immune cell density, expressed as cells per mm², in tumors with low or high CK2α expression (low CK2α, n = 14; high CK2α, n = 90). Statistical significance was assessed using an unpaired two-tailed Student’s t test. E Quantification of PD-1⁺ and PD-L1⁺ immune cells per mm² of tumor tissue in tumors with low or high CK2α expression (low CK2α, n = 14; high CK2α, n = 90). Statistical comparisons were performed using an unpaired two-tailed Student’s t test. F Correlation analysis between tumor CK2α expression (H-score) and intratumoral densities of CD3⁺, CD4⁺, CD8⁺, CD68⁺, PD-1⁺, and PD-L1⁺ immune cells across the entire cohort (n = 104). Correlations were evaluated using Pearson correlation analysis. G Representative multiplex immunofluorescence (mIF) images of lung cancer tissues with low or high CK2α expression, illustrating differential immune cell infiltration and immune checkpoint expression. Merged images and corresponding 20× magnifications are shown. DAPI, nuclei (purple); CD4, orange (Opal 620); CD8, cyan (Opal 480); CD68, gray-white (Opal 780); FoxP3, yellow (Opal 570); pan-cytokeratin (pan-CK), epithelial cells (red, Opal 690); PD-L1, green (Opal 520). Scale bar, 50 μm. Representative images from one patient per group are shown. H Representative computed tomography (CT) images of lung cancer patients before and after first-line immune checkpoint blockade (ICB) therapy. Representative images from four patients are shown. Data are presented as mean ± SEM. Statistical significance is indicated as P < 0.05 (*), P < 0.01 (**), P < 0.001 (***); ns, not significant