NR4A1 and breast cancer: Breast cancer subtyping based on the hormone receptor (HR) and HER2 expression showed that, of the 71 tumors, 68 (95.8%), one (1.4%) and two (2.8%) were HR-positive/HER2-negative, HR-negative/HER2-postive and HR-negative/HER2-negative (so-called triple-negative), respectively.