HIF1A and cancer: Lactate efflux results in an acidic extracellular tumor microenvironment, which promotes angiogenesis (60) increasing HIF1α stabilization, promoting VEGF production from cancer associated macrophages (61), enhancing hyaluronic acid production from fibroblasts (62), inducing extracellular matrix degrading cathepsins and matrix metaloproteases (63, 64), and augmenting endothelial cell PI3K and NFκb signaling (65) thereby promoting vasculogenesis.