HIF1A and breast cancer: Two studies performed in four different murine tumour cell lines as well as the MCE-7 breast cancer cell line showed that miR-20b regulates angiogenesis by targeting VEGF and HIF-1α [102, 103].While repression of miR-20b enhanced HIF-1α and VEGF protein levels in normoxic conditions, hypoxic conditions increased miR-20b levels and decreased HIF-1α and VEGF levels.