Sean Morrison

Sean Morrison is a stem cell biologist who has made provocative and influential contributions challenging strict hierarchical cancer stem cell models. Using melanoma as a model, Morrison's laboratory demonstrated that melanoma cells are remarkably plastic: rather than being organized as a rigid hierarchy, most melanoma cells can give rise to tumors with similar frequency, and tumor-initiating capacity depends more on context than on stable stem cell identity. Morrison identified OCT4, SOX2, and KLF4 neural crest factors as regulators of melanoma initiating capacity and has shown that phenotypic plasticity driven by environmental signals enables tumor cells to dynamically acquire stem-like properties.