Cancer cells mutate, and they gain the ability to release lots of those angiogenic factors, natural fertilizer, that tip the balance in favor of blood vessels invading the cancer.
癌细胞通过变异 学会了释放 多种血管生长因子，也就是我们提到的天然肥料， 来引导平衡倾向血管生长， 然后长入肿瘤。