The Hh, Notch, Wnt and BMI1 maintains the proper functionality in normal stem cells but a deregulated behavior in these pathways, owing to some alterations in the genes encoding the signaling molecules is observed in CSCs and also have been found in human tumor samples clearly stating their role in tumor development and maintenance.95, 96 As normal stem cells and CSCs share similarities in the signaling pathways, it would be extremely important while designing drugs to understand the complex biology of these pathways to destroy the CSCs and selectively sparing the normal stem cells. Here, BMI1 is linked to neoplasm.