To generate a parental pool of MTECs, mammary tumors were isolated from Hif1a floxed (DF), PyMT+ females (FVB/Nj background), and epithelial cells were transduced with ether adeno-β-gal or adeno-Cre to create HIF-1α WT and KO cell lines, respectively. Here, HIF1A is linked to breast cancer.