NEUROD1 and small cell lung carcinoma: Under these conditions, a canonical NE subtype referred to as the ASCL1 group, an ASCL1 + NE variant assigned as the NEv2 group, or SCLC-A2, an NE variant subtype termed the NEv1 group aligning with the NEUROD1 group, and a non-NE variant subtype termed the YAP1 group, were identified.