Surprisingly, Hif1α−/− PyMT+ mice had a significant increase in the number of metastatic lesions in the lung (Fig. 3d and Supplementary Fig. 3d, e) and total metastatic lesion area (Fig. 3e and Supplementary Fig. 3f, g), regardless of whether the data were normalized to total tumor weight at end point, the mouse age at sacrifice, or left un-normalized. This evidence concerns the gene HIF1A and neoplasm.