EGFR and neoplasm: When we stained for CD71 instead of EGFR to identify KLM-1 tumor cells, we found that KLM-1 cells stained with anti-CD71 R-Phycoerythrin (R-PE) were 40-fold brighter than background and have a peak clearly distinguishable from unstained cells, unlike the cells stained for EGFR (Fig. 1D).