HIF1A and breast neoplasm: Furthermore, as in the analysis of our mouse model, GSEA of these human tumor-derived transcriptomic data identifies genes with HIF1A transcription factor binding sites as enriched within brain metastases versus primary breast tumors (HIF1_Q3: P = 0.055; HIF1_Q5: P = 0.018) (Supplementary Fig. 10 and Supplementary Data 5).