Figure 3. Knockdown of APE1 regulated the immune system of lung tumor mice. (A) Significant inhibition of MDSCs in the A549+GM-CSF-siAPE1 group compared to A549+GM-CSF; (B) Analysis of Treg cells by flow cytometry; (C) Analysis of IgG levels by ELISA; (D) Analysis of GM-CSF levels. *p < 0.05, **p < 0.01, ***p < 0.001.