EGF and carcinoma: Visualization of EpCAM at the cell surface of FaDu, Cal27, Kyse30, RL95-2, and HCT8 carcinoma cells using immunofluorescence staining with EpEX-specific antibodies and confocal laser scanning microscopy confirmed a retention of EpCAM at the cell surface after treatment with EGF 9 nM for 72 hr (Fig 2K) or with EGF 1.8 nM or 18 nM for 24 hr (S3D Fig).