MKI67 and breast cancer: Upon analyzing the clinical data and ultrasound characteristics, statistically significant differences (P < 0.05) were observed among the four groups of molecular typing in female patients diagnosed with breast cancer in the following indicators: ethnicity, number of lymph node metastases, lesion size, histologic grading, expression of Ki-67, risk of postoperative recurrence, clinical stage, and features of ultrasound images (mass morphology, internal echogenicity, abnormal lymph node morphology, and internal calcification) (refer to Table 2).