ASCL1 and small cell lung carcinoma: SCLC has typically been classified into four molecular subtypes based on the expression status of distinct neuroendocrine-lineage-specific transcription factors, including achaete-scute family bHLH transcription factor 1 (ASCL1), neuronal differentiation 1 (NEUROD1), POU class 2 homeobox 3 (POU2F3), and yes1-associated transcriptional regulator (YAP1) [76].