Interestingly, unsupervised clustering of samples based on protein abundance levels of ASCL1, NEUROD1, POU2F3, and YAP1 differentiated a distinct YAP1‐driven, a mixed SCLC‐AN, and a heterogenous SCLC‐P cluster (Figure 6A). This evidence concerns the gene POU2F3 and small cell lung carcinoma.