It was reported that FNDC family of genes could be expressed in several tumor types, like breast cancer (FNDC1, FNDC8), brain and Central Nervous System cancer (FNDC3A), cervical cancer (FNDC3B), liver cancer (FNDC4), gastric cancer (FNDC5), and melanoma (FNDC6) 36, 37, which were correlated with survival of cancer patients, thus, could potentially be used as new prognostic biomarkers or promising targets for tumor therapy. Here, FNDC5 is linked to breast cancer.