With regard to the expression pattern of subtype‐specific proteins, we found that patients with high ASCL1‐ and NEUROD1‐expressing tumors tended to have late‐stage disease at diagnosis, whereas POU2F3 expression was nonsignificantly associated with early‐stage SCLC (supplementary material, Table S2). Here, POU2F3 is linked to small cell lung carcinoma.