Indeed, cats with HER2-positive mammary carcinoma also show a poor prognosis, with high clinical tumor aggressiveness, metastization capability and shorter overall-survival (OS) [1,2,8,9], with the overexpression of the epidermal growth factor receptor 2 (HER2) been reported in a range from 33% to 60% of all FMC cases [10]. The gene discussed is ERBB2; the disease is breast carcinoma.