To investigate the prophylactic effect of S100A9‐targeted CPMV in a murine triple negative breast cancer (TNBC) model, we first exposed Balb/C mice to CPMV or S100A9‐targeted CPMV via i.v. injection, and then challenged mice with luciferase‐labeled 4T1 (4T1‐Luc) cells. This evidence concerns the gene S100A9 and triple-negative breast carcinoma.