CD40 and neoplasm: Using flow cytometry analysis, we found that the percentage of CD40+ cells (CD40+%) in the splenic tissue of tumor-bearing mice (20.64 ± 3.84%, 13.86 ± 1.95% and 10.92 ± 2.45% from MFC-, LLC- and RM-1-injected mice, respectively) was significantly higher than the CD40+% in tumor-free WT mice (4.61 ± 0.34%; p < 0.05).