ERBB3 and neoplasm: Tyrosine kinase inhibitors effectively prevent autophosphorylation of EGFR and HER2 in these tumour cells; however, the transphosphorylation of HER3 is only transiently suppressed and HER3 ultimately escapes inhibition by TKIs in HER2-overexpressing tumour cells (Sergina et al, 2007).