ERBB2 and neoplasm: Cells under mitotic arrest with abnormal tubulin polymerization and the presentation of phosphohistone H3 (PHH3) induced by the intracellular influx of the payload drug were observed in the N87 tumor tissues of HER2‐ADC treated mice, and this effect was more significantly augmented by LCB‐ADC1 than by T‐DM1 (Figure 5c).