STAT3 and melanoma: Considering that many activation-signaling pathways converge on STAT3, such as EGFR, vascular endothelial growth factor, interleukin 6, focal adhesion kinase, proto-oncogene tyrosine kinase Src and others, we can state that STAT3 is an important target in melanoma therapy, and its blockage by HPF could be a crucial event among all the effects triggered by this natural compound.