HGF and melanoma: Cell distribution in the cell cycle, the expression of CCND1, the activity of signaling pathways crucial for melanoma, including the RAF/MEK/ERK pathway, WNT/β-catenin pathway, and NF-κB signaling were very similar when different growth factors, HGF, EGF and bFGF, were used in the culture medium alone, in combination or were omitted.