Identifying a missing lineage driver in a subset of lung neuroendocrine tumors.

Tumor heterogeneity of a primary histologic cancer type has major implications for cancer research and therapeutics. An important and understudied aspect of this heterogeneity is the role of transcription factors that serve as "lineage oncogenes" in a tumor type. A demonstration that different subgroups have distinct dependencies on lineage-specific transcription factors is highlighted in a relatively homogenous cancer type: the pulmonary neuroendocrine cancer small cell lung carcinoma (SCLC). Identification of these factors is providing new insights into the origin of the heterogeneity and subtype-specific vulnerabilities in SCLC and provides a template for studying heterogeneity in other cancer types.