In contrast, in a parallel study, in situ proteomic analysis performed on this cohort indicated that ERBB2 protein levels in tumor cells did decrease after 14–21 days of HER2-targeted therapy52; thus, while increased immune and stromal components of the total sample likely contributed to the reduction in ERBB2 signaling seen in global gene expression, the tumor cells themselves also exhibited reduced ERBB2 expression. The gene discussed is ERBB2; the disease is neoplasm.