The involvement of HGF in enhancing CLL cells viability by stromal cells was further confirmed by silencing HGF transcripts in the osteoblast-like cell line MG63: spontaneous apoptosis appeared in fact restored after culturing CLL cells with HGF-silenced MG63 cells but not with mock-transfected MG63 cells [21]. The gene discussed is HGF; the disease is B-cell chronic lymphocytic leukemia.