NDRG1 and breast cancer: Overall, our study includes the second larger cohort of TNBC tumor specimens in which NDRG1 is studied and demonstrates, for the first time, not only that both total NDRG1 and p-NDRG1 must be determined in tumor tissue, but also that their subcellular location and their combinations are important biomarkers to be assessed in TNBC patient tumor specimens by immunohistochemistry, as well as in other breast cancer subtypes or tumor types.