These include molecular and biochemical cellular markers (bone bridging proteins, de-γ-carboxy prothrombinogen, and alpha-fetoprotein-L3) [117], cancer stem cell markers (CD44, CD133, CD90, and EpCAM) [118], and non-cellular components (transforming growth factor beta, FGF, and vascular endothelial growth factor) [119]. Here, PROM1 is linked to cancer.