TGFB1 and cancer: In breast cancer, Nagpal and colleagues showed that miR-191 is upregulated by both HIF-1α and HIF-2α and its overexpression is responsible for cancer aggressiveness by promoting cell proliferation, and survival under hypoxia; moreover, they demonstrated that miR-191 promotes TGFβ expression thus revealing a molecular link between HIF and TGFβ signalling pathways, both pivotal in the regulation of breast cancer metastasis [63].