EGFR and neoplasm: Analysis of tumor samples by confocal and fluorescence micrographs clearly showed two primary localization patterns within patient samples: Figure 1A shows a lesion where EGFR does not undergo internalization, and the majority of EGFR proteins are localized to the cell membrane (EGFR membrane localization), whereas Figure 1B shows a typical internalizing EGFR lesion in which the cell endosomes can be observed (EGFR internalization).