Incubation with Iconitib at 0.5 μM results in kinase activity inhibition of 91%, 99%, 96%, 61% and 61%, respectively. Iconitib inhibits the proliferation of A431 and BGC-823 A549, H460 and KB cell lines with IC50s of 1, 4.06, 12.16, 16.08, 40.71 μM. When profiled with 88 kinases, Icotinib only shows meaningful inhibitory activity to EGFR and its mutants. Icotinib blocks EGFR-mediated intracellular tyrosine phosphorylation (IC50=45 nM) in the human epidermoid carcinoma A431 cell line and inhibits tumor cell proliferation.