DS-8201a may render a favorable cure with outstanding prospects for managing human epidermal growth factor receptor 2 (HER2) intimating malignancies in clinical scenarios according to its presymptomatic features. In a HER2-positive gastric cancer NCI-N87 model, DS-8201a demonstrated a HER2 expression-dependent cell growth-inhibitory effect and promoted tumor regression with a single dosage at more than 1 mg/kg. This evidence concerns the gene ERBB2 and gastric cancer.