EGF-dependent effects of 2C4 and erlotinib measured by VeraTag™ FFPE assays. SKOV3 cells were treated as described for Figure 4, but cells were fixed and made into FFPE blocks instead of lysed. Each VeraTag™ FFPE assay, listed on the X-axis, was performed on six slides. Results are depicted as the ratio of the normalized RPA of EGF and drug-exposed cells to the normalized RPA of cells that were exposed to EGF alone. Gray bar: 2C4. Black bar: Erlotinib. Values above the dashed line at ratio = 1 represent stabilization due to drug exposure, and values below the dashed line represent inhibition due to drug exposure.