The distribution of PAI1 protein was mainly in tumor cells of highgrade astrocytomas, particularly abundant in areas of vascular proliferation and in tumor cells surrounding necrotic foci, whereas it was only weekly expressed in lowgrade astrocytomas.

• PAI－1蛋白主要分布在高级别星形细胞瘤的瘤细胞和内皮细胞，尤以血管增殖部位和坏死灶周围较为显著，低级别星形细胞瘤呈低表达。