Furhermore, PDGF-A did not seem to act directly on the tumour cells, but was instead released into the space outside of the cell suggesting an effect on neighbouring cells.
而且PDGF - A似乎没有直接作用于肿瘤细胞，而是释放至细胞周围，对附近细胞产生影响。
2
And in fact, PDGF-A (and so progesterone) was found to increase the growth and viability of smooth muscle cells confirming a role to both these molecules supporting angiogenesis.