Our study demonstrates distinct functions of hypoxia in regulating angiogenesis and metastasis in different organ microenvironments and establishes HIF-1?? as a promising target for controlling organotropic metastasis of breast cancer.Keywords: breast cancer, hypoxia, HIF-1??, metastasis, noninvasive imagingIntroductionMetastasis to vital organs such as bone, lung, liver and brain is responsible f