PRF1 and neoplasm: Nevertheless, our previous study demonstrates that both costimulatory (CD40L and GITR) and coinhibitory (PD-1, CTLA-4, TIM-3, LAG3) molecules are simultaneously expressed on CD8+ T cells in the peripheral blood of tumor-bearing mice infected with a Plasmodium parasite, without affecting the secretion of effector molecules perforin and granzyme B by these T cells [17].