Tumor classification based on protein expression is used to stratify HER2-positive breast cancer patients.10,36 New classifications including both p185HER2 and t-erbB2 protein forms (p95, p110 or Δ16) could further inform selection of treatment regimen, such as kinase inhibitors (e.g., lapatinib) instead of trastuzumab alone.17,33 The scWB serves as an electrophoretic cytopathology tool, measuring both p185HER2 and t-erbB2 proteins with single-cell resolution. The gene discussed is ERBB2; the disease is breast cancer.