HGF and cancer: Cancer cells at the tumor invasive front are frequently exposed to several cytokines (eg, TGF‐β, HGF) and enzymes (eg, matrix metalloproteinase).38, 39, 40 An activated EMT program establishes autocrine signaling loops, including those of the TGF‐β and Wnt‐β‐catenin signal transduction pathways, which contribute to the CSC phenotype.41 EMT program also contributes to CSC function through several intracellular signaling pathways.