We constructed the LPS‐induced B16 tumor‐bearing mice model without a GFP fluorescence signal, CD11b/ Gr‐1 double positive cells were obtained by flow cytometry sorting, and whether CD11b/ Gr‐1 double positive cells contained melanoma antigen A (Melan‐A) specific to B16 cells was detected. The gene discussed is ITGAM; the disease is neoplasm.