ERBB2 and neoplasm: Three types of cellular distributions have been identified based on HER2 status heterogeneity: “clustered”, featuring two distinct tumor clones (one with HER2 amplification and another with a normal status); “mosaic”, where a diffused mix of cells with different HER2 states exists; and “dispersed”, characterized by isolated HER2-amplified cells amidst a majority of HER2-negative tumor cells.