YBX1 and breast cancer: Several studies illustrated that YB-1 overexpression is associated with a poor prognosis for patients with malignant tumors such as head and neck cancer [16], non-Hodgkin lymphoma [17], breast cancer [18], osteosarcoma [19], non-small cell lung cancer [20], gastric cancer [21], and esophageal squamous cell carcinoma [22].