HIF1A and cancer: HIF-1 activation in cancer and stromal cells contributes to tumour malignancy.8, 9 We recently revealed that Munc18-1-interacting protein 3 (Mint3) activates HIF-1, even during normoxia, in cancer cells and macrophages.10, 11, 12, 13 Mint3 binds to and suppresses factor inhibiting HIF-1 (FIH-1), thereby activating HIF-1.