The presence of a subpopulation expressing stem cells markers (for example, CD133 and Nestin) with the ability to differentiate into more mature phenotype and manifesting resistance to cytotoxic drugs due to a high drug efflux capacity [21] is the basis of the concept of Cancer Stem Cells (CSC) in almost every aggressive tumor, especially in neuro-oncology [22]. Here, PROM1 is linked to cancer.