To determine the frequency in-vivo of a HCC1954-type proteomic responses to HER2-targeted therapy, we analysed the RPPA data generated from the NCT00524303 clinical trial, which assessed the impact of treatment with either trastuzumab, lapatinib or a combination of both on signalling alterations in 38 HER2-positive breast cancers (Figure 4). The gene discussed is ERBB2; the disease is breast cancer.