NEUROD1 and small cell lung carcinoma: In addition, considering the better outcomes obtained in cMyc-positive tumors, efforts should be made to apply the concept of precision medicine even in SCLC; the four subgroups based on differential expression of transcription factors ASCL1, NEUROD1, POU2F3 and YAP1 could provide a reproducible method of classifying SCLC for this scope, considering that cMyc tends to be overexpressed in SCLC-N subtype.