IGFBP5 and cancer: The C18 cluster expressed genes associated with stem cell and cancer-initiating cell features, including activated leukocyte cell adhesion molecule (ALCAM)/CD166,33Musashi 2 (MSI2),34SRY-box transcription factor 2 (SOX2),35SOX1,36insulin-like growth factor binding protein 5 (IGFBP5),37L-Myc (MYCL),38prominin-1 (PROM1)/CD133,39transcription factor 3 (TCF3),40 and the neuroendocrine marker chromogranin A (CHGA) (Fig. 3c).