ASCL1 and small cell lung carcinoma: Nowadays, next-generation gene sequencing-based gene expression analysis of human tumors and cell lines revealed that SCLC comprised four distinct subtypes based on the expression of ASCL1(SCLC-A), NeuroD1(SCLC-N), YAP1(SCLC-Y), and POU2F3(SCLC-P) [24].