GZMB and cancer: Subsequent analysis of mouse cancer tissues through flow cytometry revealed that RNase1 knockdown in 4T1 cells increased the proportion of CD8+ T cells expressing effector cytokines, including granzyme B (GB) and IFN‐γ (Figure 4D), and reduced expression of ICs such as Pd‐1 and Tim‐3 (Figure 4E) on CD8+ T cells in the TME.