Angiogenesis in Spontaneous Tumors and Implications for Comparative Tumor Biology

Figure 1

Angiogenetic sprouting: after stimulation with angiogenic factors, the quiescent vessel dilates and an endothelial cell tip cell is selected. Stalk cells behind the tip cell proliferate, elongate, and form a lumen, and sprouts fuse with an adjacent vessel sprout to establish a perfused neovessel, (from [8], modified).