These studies were single-center studies, and conducted in the UK [25, 32], Belgium [31], France [23], Singapore [35], Algeria [22], and China [33, 34], which evaluated several types of breast cancer, including TNBC, HER2 + breast cancer, invasive ductal carcinoma of the breast, and breast ductal carcinoma in situ. The gene discussed is ERBB2; the disease is ductal breast carcinoma in situ.