NDRG1 and breast cancer: In our study, breast tumor samples with histology in moderate and poor grades, metastasis, TNM at stages III/IV, and lymph invasion status were found to be more frequent in methylation than with a high histological grade, no metastatic disease, TNM at stage І, and no lymph invasion, which showed that NDRG1 methylation plays an important role in the course of the histological grade, metastasis, TNM stages, and lymph invasion status for breast cancer.