Therefore, the tumor cell GA‐targeting self‐assembled peptide (NF‐1) is tailored, and confirmed that NF‐1 treatment can achieve an effective immunotherapy and found that tumor cell‐derived GA‐dependent migration inhibitory factor (MIF) mediates the formation of immunosuppressive network in breast cancer (BRCA) through multi‐omics analysis, in vivo, and in vitro experiments. The gene discussed is NF1; the disease is breast cancer.