In particular, recent study demonstrated that the fibrosis progression in non-alcoholic steatohepatitis (NASH) is NKT cell dependent, and NKT cell-mediated fibrogenesis requires Hh and OPN, the latter of which, as an Hh-regulated cytokine, can further activate HSCs and promote fibrogenesis in an autocrine or paracrine fashion (39). Here, SPP1 is linked to metabolic dysfunction-associated steatohepatitis.