Like Wnt signaling pathway aberrant activation of Hedgehog pathway due to overexpression of smoothened or due to various growth factors (fibroblast growth factor 5 (FGF5) and collagen), EMT, MET, CAF have been observed to be involved in maintenance, proliferation and, stemness of BCSCs [60,61,65,85,86,87] Therefore, the Hedgehog pathway is considered to be an important regulatory pathway for maintenance of stemness in breast cancer cells [69]. This evidence concerns the gene FGF5 and breast cancer.