Although NE subtypes based on the expression of those TFs have been previously described in SCLC7,10, the existence of these subtypes in treatment-emergent NEPC was unanticipated, as ASCL1 and NEUROD1 have been specifically associated with lung NE cells8,9,27, the putative cell of origin of the de novo SCLC. Here, NEUROD1 is linked to small cell lung carcinoma.