PRF1 and neoplasm: The increased proliferation and activation of effector CTLs provides further evidence that FK@IQ-4T1+L treatment combining the presentation of tumor antigens and JQ1-mediated inhibition of the PD-L1/PD-1 blockade effectively activates TNF-α+/IFN-γ+ CTLs capable of killing tumor cells by secreting various cytokines including perforin, granzymes, and granulysin43.