Figure 7. Immunostaining showed different vascular phenotypes with different protein expressions upon cell suspension and suppression of ANPEP expression. Photomagnification of tumor tissues derived from (A) adherent melanoma cells or (C) shLuc-transfected cells with HE stain and immunostaining of CD31 showed vascular structures. Positive ANPEP, SDC1, and integrin β4 expression in these tumor tissues were also presented. Filled arrow, vascular cavities with integrin β4-positive cells-surrounded. Empty arrow, vascular cavities with integrin β4-positive cells. No vascular structures with CD31/ANPEP/SDC1/integrin β4 expression were seen in those from (B) suspended melanoma cells or (D) shANPEP-transfected cells. The arrows indicated the locations of RBC-infiltrated cavities.