Detection of killer cytokines IFNG/IFN-γ, TNF/TNF-α, and GZMB secreted by CD8+ T cells revealed that reduced circGRAMD4 expression relieved tumor cell-induced immunosuppression, whereas increased circGRAMD4 expression suppressed the production or release of these immune factors (Figure 2E, S4B). Here, GZMB is linked to neoplasm.