Considering only age distribution, the average age of breast cancer patient among Chinese was lower than that of northern America and Europe (mean 47.5 years),4,12–14 which was similar to Korea and Japan.21 Luminal B (high Ki-67) tumors arose in even younger patients than those with TN tumors (mean 43.0 years vs 47.4 years). Here, MKI67 is linked to breast cancer.