More importantly, effector CD8+ T cells producing IFN-γ and granzyme B were significantly reduced in tumors and draining lymph nodes from Ccdc134 TKO mice, relative to WT mice, and Ccdc134 TKO CD8+ T cells expressed lower levels of Ki67 than WT controls in the tumor microenvironment (Figure 4D). The gene discussed is CD8A; the disease is neoplasm.