Co‐culture with murine bone marrow–derived macrophages revealed that tumor‐associated macrophages (TAMs) significantly increased the IC50 of cisplatin in AGS gastric cancer cells, more tumoral LIF expression further enhanced TAM‐induced resistance of tumor cells to cisplatin, but the deficiency of LIF in tumor cells obviously diminished this effect of TAMs indicating their role in reducing tumor cell chemosensitivity [35]. This evidence concerns the gene LIF and neoplasm.