A large number of studies suggested that the overexpression of DEK was associated with poor survival of patients with various types of solid tumors, including lung cancer [11–13], hepatocellular carcinoma [14–16], colorectal cancer [17–19], breast cancer [20–22]; gastric cancer [23, 24], prostate cancer [25], pancreatic cancer [26], melanoma [27–29], and ovarian tumors [30]. Here, DEK is linked to breast cancer.