KRT88P and breast cancer: The intracellular uptake of fluorescently labelled Alexa FluorTM 488 WT-HBc, ΔHBc and ZHER2-ΔHBc in breast cancer cells; MDA-MB-468, MDA-MB-231, SKBR-3 and BT-474 was evaluated with flow cytometry using the FL-1 detector.