Moreover, we designed the OVA&si-Irg1-LNP, which contained OVA mRNA and Irg1 small interfering (si)RNA (si-Irg1), suppressed Irg1 expression, and itaconate secretion in vitro and in vivo. More importantly, OVA&si-Irg1-LNP enhanced anti-tumor efficacy alone or combined with anti-programmed cell death-1 (anti-PD-1) antibody and showed good safety. This evidence concerns the gene PDCD1 and neoplasm.