In a meta-analysis of Ki-67 involving 12,155 early breast cancer patients, a high Ki-67 index was significantly related to worse prognosis, with an HR of 1.93 (95% CI: 1.74-2.14; P < 0.001) for disease-free survival (DFS) and an HR of 1.95 (95% CI: 1.7-2.24; P < 0.001) for OS [27]. Here, MKI67 is linked to breast cancer.