HIF1A and breast cancer: In this study, we demonstrate (a) increased ITGB3 mRNA and protein expression in hypoxic BC cells that is mediated by HIF-1; (b) increased incorporation of ITGB3 on the surface of EVs derived from hypoxic BC cells; (c) increased short-term uptake in the brain of blood-borne ITGB3+ EVs derived from hypoxic BC cells; (d) increased permeability of brain ECs exposed to ITGB3+ EVs; (e) increased BC cell transmigration of a brain EC monolayer exposed to ITGB3+ EVs; and (f) increased brain colonization by hypoxic BC cells that was HIF-1α and ITGB3 dependent (Figure 10).