Moreover, the biodistribution of 131I-trastuzumab in mice bearing HER2 positive tumors showed maximum higher tumor uptake at 24 h, but there is no significant difference from combination of 131I-trastuzumab and lanatoside C. Biodistribution studies in nude mice showed that 131I-trastuzumab targeted the tumors overexpressing the Human HER2 receptor in vivo. The gene discussed is ERBB2; the disease is neoplasm.