Additionally, the CYP19A1 siRNA remarkably inhibited PD-L1 expression on tumor cells (Fig. 9J), induced vascular normalization, as manifested by an obvious decrease in the hypoxia-inducible factor (HIF) -1α level and an increase in CD31+ αSMA+ cells number (Fig. 9K and L). Here, PECAM1 is linked to neoplasm.