In OE19 HER2+ tumour xenografts, a single dose of 1 nmol of either T-MMAE or T-DM1 (∼7.7 and ∼7.4 mg kg−1, respectively) were equally efficacious in slowing tumour growth compared with control or trastuzumab by day 14 (Fig. 5b, Supplementary Table 4). The gene discussed is ERBB2; the disease is neoplasm.