PROM1 and cancer: According to the brain tumour cancer stem cell model, a subpopulation of cancer cells possesses the capacity of self-renewal, tumour formation and the capability to form progeny with a more restricted fate.10 In GBM, several stem cell candidate markers have been explored, however, out of these, CD133 is the most studied.7,11 CD133+ GBM cells are considered stem cells because of their ability to self-renew, differentiate and to initiate tumour formation in vivo.