ERBB2 and breast cancer: As shown in Fig. 5A, treatment of BT-474 (ERBB2 amplified) breast cancer cells with increasing concentrations of neratinib (up to 250 nM) for 1 h led to a dose dependent decrease in the expression of downstream effectors of HER2 including phosphorylated AKT (pAKT) and ERK (pERK).