A HER2-targeted ADC (trastuzumab deruxtecan, SYD985) prepared by linking trastuzumab with a new cleavable linker to the dual doxorubicin prodrug secoDUBA showed antitumor activity in preclinical breast and gastric cancer models with low HER2 expression [111, 112]. The gene discussed is ERBB2; the disease is gastric cancer.