Autophosphorylation of EGFR shows similar inhibition profile as the AP-1- bla ME180 functional cellular assay. Immunocytochemistry with phospho-specific antibodies demonstrates the same inhibition profile as the AP-1 activation assay performed using the ME180 CellSensor. Fluorescence was measured from the Alexa fluor 488 and 594 labelled secondary antibodies used for detection (Panel A). Percent inhibition was determined in comparison to untreated sample and represents the mean of (± SEM) eight independent data points (n = 8). Images were obtained from the Alexa fluor 488 labelled secondary antibody under fluorescent microscopy (Panel B).