In contrast, in the tumor, virtually no naïve CD8+ T cells were detected, and the main effect was observed in anti-PD-1 treated Suv39h1-KO mice, in which the proportion of memory cells (CD44hiCD62Lhi) was significantly lower, while both the proportion and the absolute number of effector CD8+ T cells were significantly higher (Fig. 1F). This evidence concerns the gene SUV39H1 and neoplasm.