When ZHER2:342‐36FSY‐CR8 ADCN specific binds to human epidermal growth factor receptor 2 (HER2) on cancer cells, the FSY36 of ZHER2:342 approaches to the His490 of HER2 and ultimately reacts with each other to form a covalent bond via SuFEx reaction. This evidence concerns the gene ERBB2 and cancer.