POU2F3 and small cell lung carcinoma: To explore the correlation between tumor spatial heterogeneity patterns and the previously established molecular subtypes (SCLC‐A, SCLC‐N, SCLC‐P, and SCLC‐Y) of SCLC defined by RNA‐seq, we extracted the spatial expression of four key transcription regulators (ASCL1, NEUROD1, YAP1 and POU2F3) as previously described by Rudin et al.[10] to assess SCLC molecular subtypes across 79 ROIs in 25 patients.