YAP1 and small cell lung carcinoma: Although numerous SCLC subtypes have been reported in the literature (achaete–scute complex homolog-like (ASCL1); neurogenic differentiation factor 1 (NEUROD1); atonal bHLH transcription factor 1 (ATOH1); POU class 2 homeobox 3 (POU2F3); Yes1 associated transcriptional regulator (YAP1); inflamed)1,9 a recent analysis of 174 SCLC tissue samples revealed the predominance of ASCL1, NEUROD1 and double-negative subtypes in clinical samples17.