CD4 and neoplasm: The number of all the subclasses of lymphocytes was significantly higher in the tumor and peri-tumoral compartment, compared to the intra-epithelial compartment and normal pancreatic parenchyma (CD3+ lymphocytes 97.7 vs. 2.66 vs. 31.68, p < 0.001; CD4+ lymphocytes 44.7 vs. 0.51 vs. 11, p < 0.001; CD8+ lymphocytes 62.74 vs. 2.32 vs. 26.3, p < 0.001; CD20+ lymphocytes 44.37 vs. 0.04 vs. 5.49, p < 0.001, respectively).