Fifteen years ago we showed for the first time that stem cells from the adult human brain can differentiate into functional neurons, and that it is possible to generate a small nervous system with numerous neurons that fire action potentials and communicate via synapses, from a single stem cell harvested from the adult human brain.

Simultaneously we started to grow cells from GBMs. A population of cells from these tumors turned out to have stem cell-like properties. We showed that a GBM only can be transferred from one animal to another by transplantation of cells from the GSC subpopulation, in keeping with other results indicating that it is this subpopulation that is responsible for rencurrence, growth and drug resistance. We have therefore characterized GSCs quite extensively.