Fig. 3

IL-35⁺Foxp3⁺ cells are induced in the tumoural (TU) region of patients with non-small cell lung cancer (NSCLC). a Correlation between IL-35⁺ cells per area unit detected via immunohistochemistry (IHC) and Foxp3/β-Actin protein levels quantified by western blot in the control (CTR) and TU area of patients with NSCLC (ADC_CTR = 0, ADC_TU = 1; SCC_CTR = 4, SCC_TU = 4). b Left: Representative images of double IHC for programmed cell death ligand 1 (PD-L1) (brown) and thyroid transcription factor 1 (TTF-1) (blue) on paraffin-embedded lung tissue from the TU region of a patient with ADC (×12 and ×60 magnification). Right: Correlation between IL-35⁺ and PD-L1⁺TTF-1⁺ double-positive cells per area unit detected via IHC in the TU (NSCLC_TU = 16) lung tissue of NSCLC patients. c Representative images of double IHC for interleukin (IL)-35 (brown) and Foxp3 (blue) on paraffin-embedded lung tissue from a control patient without lung carcinoma (HC) as well as from the CTR and TU region of patients with ADC (×12 and ×60 magnification). d Quantification of IL-35⁺Foxp3⁺ double-positive, IL-35⁺ single-positive, and Foxp3⁺ single-positive cells per area unit upon IHC staining of paraffin-embedded lung tissue arrays obtained from HC control patients (HC = 10) as well as from patients who suffered from ADC (ADC_CTR = 16, ADC_TU = 17) and SCC (SCC_CTR = 12, SCC_TU = 15) subtypes, collectively grouped as NSCLC. Data are presented as mean ± SEM and significance levels are indicated as follows: *p < 0.05, **p < 0.01, ***p < 0.001