The present study found that G-CSF-induced MDSC accumulation in tumors is responsible for the chemoresistant nature of G-CSF-producing cervical cancer: the tumor-derived G-CSF stimulates the production of MDSC, prolongs the survival of MDSC, and enhances the production of Bv8, a pro-angiogenic molecule. The gene discussed is CSF3; the disease is cervical carcinoma.