PROM1 cell signaling in cancer. The first intracellular domain of PROM1 promotes WNT-β-Catenin signaling pathway and tumorigenesis by interacting with HDAC6 (37). The C-terminal cytoplasmic domain of PROM1 activates PI3K-AKT signaling pathway and tumorigenesis by interacting with PI3K p85 (41). CSC, cancer stem cell.