HGF and myeloproliferative neoplasm: Data from different authors about a relationship between disease outcome and HGF or c-MET overexpression appear however discordant in some types of malignancies (i.e., DLBCL, HD), while for others, such as MM or AML and Ph+MPN, several reports have univocally confirmed a pivotal role of HGF/c-MET in pathogenesis.