Thus, while endogenous IL-15 deficiency induces profibrotic cytokines (e.g., TGF-β) and myofibroblast accumulation in allergic lung [17] and chronic pancreatitis [18] models, pharmacological IL-15 delivery ameliorates fibrosis by down-regulating TGF-β and by restricting the TGF-β1-induced myofibroblast differentiation. This evidence concerns the gene IL15 and chronic pancreatitis.