PTPRC and breast cancer: Circulating tumor cells are defined as PanCK‐positive, CD45‐negative, and DAPI‐positive cells as shown in Figure 1A. Based on the biopsy results, 366 patients suspected of having BC were divided into one group of 130 BC patients and another group of 236 patients with BBD, including breast fibroadenomas, breast adenosis, mammary duct ectasia, breast cysts, and fat necrosis of the breast.