PROM1 and central nervous system cancer: CD133, also known as prominin-1, was first described as a cell surface marker on hematopoietic stem cells.(13) It is a five-transmembrane glycoprotein composed of an N-terminal extracellular tail, two small cytoplasmic loops, two large extracellular loops containing several potential glycosylation sites, and a short C-terminal intracellular tail.(14) CD133 has been used as a marker to identify CSCs derived from primary solid tumors.(1) Its expression is also used as a prognostic marker of gliomas.(15)