Developmental signaling pathways in cancer stem cells of solid tumors

► Cancer may be viewed as a disease in which normal cellular homeostasis is disrupted. ► Developmental signaling pathways are often deregulated in cancer. ► Cancer stem cells have been identified and characterized in many solid tumors. ► Breast, brain and colon cancer stem cells are the most well-characterized. ► Hh, Notch and Wnt pathways play important roles in normal and cancer stem cells.