Interestingly, the human tumor EC-like population had high plasma membrane EGFR and IGFR concentrations (~21,000/cell and ~20,000/cell, respectively) (Figure 2C), consistent with qualitative findings of higher EGFR on breast carcinoma-derived ECs compared to normal ECs (Amin et al., 2006). Here, EGFR is linked to breast carcinoma.