PROM1 and gastrointestinal stromal tumor: Neither tissue nor tumor specific, CD133 identifies with stem/progenitor cells, as well as a host of CSC from variety of tumors notably GBM [12], colon [13], lung [14],and prostate [15] etc. Although, CD133 protein expression was found to be universal expressed in GIST [16], [17], it might not be a good biomarker for CSCs when using protein assay.