Indeed, tumor cellularity, defined as the proportion of evaluated cells representing invasive tumor cells, was found to be higher in HER2-enriched tumors than in normal-like tumors (17.7% vs 6.4%, two-sided t-test p = 5.5e-6), while no such difference was observed between IC5 and other integrative clusters (15.5% vs 13.0%, p = 0.39) (Supplementary Fig. 1). Here, ERBB2 is linked to neoplasm.