ERBB2 and neoplasm: (Gerlinger et al., 2012; Hull, 2005; Navin et al., 2010; Navin and Hicks, 2010) Clearly, misclassification of a tumor as ‘HER2 negative’ based on the primary site may have implications on outcomes for that patient if the metastatic site had evolved to acquire HER2 amplification (Figure 2B).