Lastly, unlike in neuroblastoma10, we found no difference in DLK1 expression by IHC between pre- and post- ADCT-701 treated ACC PDX tumors (Supplementary Fig. 8E) suggesting that selection and outgrowth of DLK1 negative cells does not contribute to ADCT-701 acquired resistance in ACC. The gene discussed is DLK1; the disease is adrenal cortex carcinoma.