ASCL1 and small cell lung carcinoma: SCLC can be classified into neuroendocrine subtypes (SCLC-A, SCLC-N) and non-neuroendocrine subtypes (SCLC-Y, SCLC-P) based on its expression of ASCL1, NEUROD1, POU2F3, and YAP1; SCLC-A represents 50–70% of cases [104].