Moreover, in vascular co-option (Figure 11B,H,N and Figure 12) areas, the blood vessels, showing a reduced CD31 expression compared to sprouted vessels, appear surrounded by P-gp- or S100A10-positive tumor cells with a not-indifferent expression of mitochondria (Figure 11H and Figure 12), indicative of boosted metabolic activity in tumor cells. Here, PGP is linked to neoplasm.