EGFR and neoplasm: In our study, EGFR mRNA counts were generally equally high across all tumor cohorts and SES suggesting no relationship with tumor status (data not shown) but rather that the presence of high levels of active EGF (and VEGF-A) in the pericellular space of metastatic tumors may be responsible for enhanced stimulation of EGFR-mediated signaling pathways (Figure 7).