EGF and neoplasm: In vitro, CSCs can grow when cultured in low-adherence cell culture conditions in the presence of growth factors, such as fibroblast growth factor-2 (FGF-2) and epidermal growth factor (EGF) generating floating spheroid colonies (melanospheres) and express markers of epithelial-to-mesenchymal transition (EMT) associated with a highly invasive behavior; in vivo, the inoculation of CSCs in nude mice at limited dilutions has been widely reported to give rise to newly formed tumors sharing the characteristics of the primary tumor mass [63,65,72,73,74,75,76,77].