HGF and melanoma: Straussmann et al. reported that in BRAF-mutant melanoma under RAF inhibition, the stromal secretion of hepatocyte growth factor (HGF) activates MET (Mesenchymal—Epithelial Transition factor) signaling, reactivation of the MAPK (Mitogen Activated Protein Kinase) and PI3K/AKT pathways, and immediate resistance to RAF inhibition [70].