ASCL1 and small cell lung carcinoma: Samples in cluster Carcinoid A1 were also characterised by high-expression levels of the delta like canonical Notch ligand 3 (DLL3, 75% with FPKM > 1) and its activator the achaete-scute family bHLH transcription factor 1 (ASCL1) (Fig. 5a and Supplementary Data 10), similar to SCLC and LCNEC (Fig. 5b); however, the expression levels of NOTCH genes did not differ between the different groups (Supplementary Fig. 24).