Li et al. found that miR-26a-5p is a protective element to protect breast cancer from attack, in contrast, OTUD6B-AS1 and MTDH are destructive elements of breast cancer, and miR-26a-5 is down-regulated through OTUD6B-AS1/miR-26a5p/MTDH pathway. This evidence concerns the gene MTDH and breast cancer.