Differential expression of ASCL1 and NEUROD1 defines A- and N-type human SCLC, which likely derives from NE cells.55 Interestingly, these two TFs coincide with the scRNA-seq marker genes and scATAC-seq TF motif enrichment of our fetal NE cells (Figures 6B and 7B). This evidence concerns the gene NEUROD1 and small cell lung carcinoma.