HGF and systemic lupus erythematosus: Level of HGF mRNA was decreased in SLE BMSCs and downregulated by SLE serum and recombinant TNF-α, which was diminished after TNF-α blocking or adding TPCA-1 to the cultures, supporting that HGF plays a role in TNF-α and IKK-β induced impairment of SLE BMSC migration.