SPP1 and Hepatic fibrosis: NKT cell secretions to cytokines were reduced following treatment with vitamin D, and this is a crucial step in giving them antifibrotic properties, unlike several studies that suggest Many studies suggest that NKT cells promote liver fibrogenesis by producing pro-fibrotic cytokines such as IL-4, IL-13, hedgehog ligands, and OPN; however, NKT cells may also attenuate liver fibrosis under certain conditions by killing pHSCs and by producing IFN-γ (Gao and Radaeva, 2013).