We modeled biodistribution data from Mandikian et al. [9] for two TCB formats with differing CD3 affinities: one TCB lacking tumor target binding (glycoprotein D (gD)-CD3 TCB) and another TCB with a target arm binding to the receptor called the Human Epidermal growth factor Receptor 2 (HER2) (HER2/CD3 TCB) in a transgenic mouse model. This evidence concerns the gene ERBB2 and neoplasm.