Which of the following statements about angiogenesis in tumors is TRUE?
1
Tumors larger than 2 cm can sustain themselves without angiogenesis.
2
VEGF (vascular endothelial growth factor) plays a key role in inhibiting angiogenesis.
3
Angiogenesis in tumors helps supply nutrients and oxygen, supporting tumor growth.
4
Inhibiting angiogenesis has no impact on cancer progression.