“…Given that ATL is a malignancy of activated mature T cells, the leukemic cells secrete a variety of cytokines, including tumor necrosis factor-a and interleukin-1b (Wano et al, 1987;Yamada et al, 1996). Both of these cytokines are potent inducers of HGF expression in fibroblasts (Matsumoto et al, 1992;Tamura et al, 1993), suggesting that ATL cells may indirectly increase the plasma HGF level through secretion of these cytokines and consequent activation of fibroblasts.…”