The ratios of total PFK-1 to β-actin expression were 0.272±0.051 vs. 0.139±0.032 (P=0.033), 0.303±0.064 vs. 0.142±0.022 (P=0.029) and 0.370±0.040 vs. 0.136±0.030 (P=0.018), respectively, between the human breast cancer and paracancer tissues of each clinical stage. Here, PFKM is linked to breast cancer.