CD40 and neoplasm: The apoptosis of the MDSCs was found to significantly increase following treatment with agonistic anti-CD40 (Fig. 3B), and compared with the PBS treatment, the percentage of apoptotic tumor-infiltrating MDSCs increased from 71.37±2.68 to 79.09±3.29% (mean ± SEM; P=0.0352; Fig. 3A and B).