PROM1 and hepatocellular carcinoma: CD133+ is a transmembrane glycoprotein that known as an important cell surface marker of the putative normal liver stem cells “oval cells” as well as cancer stem cells (CSCs) [3–6]. In line with this, the increased expression of CD133+ was found to be correlated with advanced stages of HCC [7,8]. A special attention is given to the naive circulating CD133+ cells and its clinical significance in HCC prognosis.