NEUROD1 and small cell lung carcinoma: SCLC-A and SCLC-N are characterized by the expression of ASCL1 and NEUROD1, respectively, which are involved in neuroendocrine differentiation and characterized as “neuroendocrine subtypes.” SCLC-P is considered a “non-neuroendocrine subtype” as it is characterized by POU2F3 expression, which drives the expression of tuft cells in the mucosal epithelium[41].