NEUROD1 and small cell lung carcinoma: None of the malignant cells mapped to the SCLC-N or SCLC-Y subtypes, probably due to their low frequencies among SCLC subtypes.9 Strikingly, three patients (P4, P10, and P11) expressed high levels of ASCL1 and variable levels of NEUROD1; this was termed the SCLC-A/N subtype in our study (Supplementary Fig. S4b).