Fibrosin is a lymphokine secreted by activated lymphocytes that induces fibroblast proliferation FBRS (or FBS1) gene, encoding fibrosin (or fibrosin-1), was first cloned by Prakash et al. and was found to be able to stimulate several biological activities related to scarring as a fibrogenic lymphokine. Fibrosin is secreted by activated lymphocytes that induce fibroblast proliferation. In vitro application of fibrosin stimulates expression of alpha smooth muscle actin fibers and plays an important role in up regulating the appearance of myofibroblasts during wound healing and possibly in fibrotic diseases. Fibrosin is also implicated in alcohol-induced hepatic fibrosis in vivo.