ERBB2 and cancer: The latent bioreactive unnatural amino acid fluorosulfate‐L‐tyrosine (FSY) at site 36 of affibody‐molecular glue drug conjugate (ZHER2:342‐36FSY‐CR8) comes into close proximity with the histidine at site 490 of HER2 (human epidermal growth factor receptor 2) and ultimately reacts with each other to form a covalent bond via proximity‐enabled sulfur‐fluoride exchange (SuFEx) reaction, as a result, covalent ZHER2:342‐36FSY‐CR8 irreversibly binds to HER2 on cancer cells.