In terms of the levels of MDSCs, PMN-MDSCs, M-MDSCs and Tregs in the peripheral blood of breast cancer patients, no statistically significant correlations were found with age, menopause status, histological grading, vascular invasion, molecular subtypes, ER level, PR level, Her-2 level, Ki-67 level and AR level (all P > 0.05). The gene discussed is MKI67; the disease is breast cancer.