A. Histogram plots comparing the percentage of CD8+ T cells in peripheral blood from pancreatic cancer patients (n=31) and healthy donors (n=20). The proportion of CD8+ T cells significantly decreased in patients vs. healthy donors (p=0.00195). B. Percentage of double positive (perforin positive and CD8 positive) lymphocytes. Representative flow cytometric proļ¬le of perforin expression on the gated CD8+ T cells (Malignant vs. healthy, n=15, respectively). No significant difference was seen between the two groups (p>0.05, data not shown). C. The levels of perforin expression (mean fluorescence intensity, MFI value) in CD8+perforin+ lymphocytes. The MFI value in control group was significantly higher than that in the patients ( p=0.00208).