ERBB2 and Skin rash: Indeed, since the ligand‐dependent activation of HER2 plays an essential role in cardiac development and physiological function of the adult heart, the current anti‐HER2 therapies induce significant cardiotoxicities [11, 30], as well as high incidence of diarrhea, nausea, and skin rashes due to the inhibition of EGFR/HER1 function in epithelial tissues such as skin and mucosa [31, 32].