T cell killing assays revealed that co-delivery of siRNA targeting both EGFR and PD-L1 by the PEG12-KL4 peptide significantly enhanced the cytotoxic effects driven by CD8+ T cells, thereby illustrating the feasibility of this dual silencing of EGFR and PD-L1 approach against NSCLC. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.