HGF and cancer: Cancer cells and CAFs often work in tandem, wherein cancer cells stimulate the activation of CAFs to encourage the growth of the tumour, while CAFs secrete numerous growth factors such as hepatocyte growth factor (HGF) and transforming growth factor beta (TGF-β), and by secretion of host-derived cytokines and chemokines that drive the tumour to develop and disseminate [14,15].