NEUROD1 and neoplasm: To investigate whether these TFs are co-expressed in the same tumor cells or in distinct tumor sub-populations, we studied five distinct fragments of liver metastasis (FLMs) obtained at autopsy from a patient diagnosed with NEPC available as both Optimal cutting temperature compound (OCT compound) frozen and formalin-fixed paraffin-embedded material, and performed RNA-seq to assess expression levels of ASCL1 and NEUROD1. These levels showed a range of coexpression of the two TFs with FLM3 showing the highest relative expression of NEUROD1 to ASCL1 (Supplementary Fig. 3c).