ERBB2 and neoplasm: The patients were divided into 2 groups depending on the degree of trogocytosed-HER2+ tumor-infiltrated immune cells (Figure 4B); the patients who showed a high degree of HER2 expression on tumor-infiltrated immune cells (by TI HER2 trogocytosis) demonstrated a significantly greater probability of achieving a pCR with trastuzumab-based PST (Figure 4C).