Tissues are often organized into cellular hierarchies characterized by progressive differentiation and developmental commitment.

Malignant gliomas are lethal cancers that display cellular hierarchies with cancer stem cells at the apex.

Yet how oncogenic alterations interact to control cellular hierarchies during tumor initiation and progression is largely unknown.

Glioblastomas are highly lethal cancers that contain cellular hierarchies with self-renewing cancer stem cells that can propagate tumors in secondary transplant assays.