DLK1 and metastatic neoplasm: To validate these RNA-seq data, we performed DLK1 IHC across our cohort of ACC metastatic tumors and found 97% (n = 28/29) of ACC patients were DLK1+ by cytoplasmic/membranous scoring (mean H-score 147, range 10-300) reflecting a mix of intensity and distribution of DLK1 in ACC (Fig. 1D), which is similar to recent DLK1 IHC data from a large cohort of ACC tumors17.