Qu et al. evaluated the molecular subtypes of 146 primary SCLC tumors using IHC and found that 17.6% and 2.8% of SCLC cases were positive for two and three subtype markers (ASCL1, NEUROD1, POU2F3, and YAP1), respectively [70]. The gene discussed is POU2F3; the disease is small cell lung carcinoma.