TNFSF12 and cholestasis: In particular, macrophage-derived TNF-related weak inducer of apoptosis kinase (TWEAK) induced expansion of progenitor cells and proliferation of bile ducts in healthy mice, while fibroblast growth factor–inducible 14 (Fn14) deficient mice or neutralisation of TWEAK prevented the expansion of progenitor cells in cholestasis mice [121,122].