Fig. 4.

ISG15 knockdown decreases PDL-1 expression and increases CD8+ T cell intratumor infiltration in PDAC tumors. a PDL-1 expression. The same tumors from Fig. 2 were stained by immunohistochemistry (IHC) using anti-PDL-1 antibody. Lower panel shows the quantitation of PDL-1 expression was significantly decreased in ISG15 knockdown tumors as compared to wild type (*p < 0.001). b CD8⁺ T-lymphocyte expression. The same tumors from Fig. 2 were stained by IHC using anti-CD8 antibody. Lower panel. The quantitation of five low power (×10) fields was performed by manually counting positive cells (*p < 0.04 as compared to wild type)