MRC1 and neoplasm: In the ovarian tumor, the mRNA‐PbAE complex could significantly reduce Ly6C–F4/80+CD206+ M2‐like macrophage population (2.6% ± SE/2.1% vs. 43% ± SE/15.6% in controls) and enhance M1‐like macrophage population (from 0.5% ± SE/0.2% to 10.2% ± SE/4.1%), then increase pro‐inflammatory IL‐12 (3.4‐fold higher), IFN‐γ (8.4‐fold higher), and TNF‐α (1.5‐fold higher) cytokines and tumor infiltration of T cells (i.e., CD8+ T cells, 10.6‐fold and CD4+ T cells, 3,5‐fold).