Eight-week-old male SPF mice were randomly grouped and received control or 10 mg/kg GW4869 by daily gavage under HFHCD plus nicotine water treatment for 20 weeks (Nicotine, n = 5 mice; Nicotine + GW4869, n = 7 mice). a, Ileal ceramide profiles. b, Liver weights. c, Liver weight–to–body weight ratios. d, e, Serum ALT (d) and AST (e) levels. f-j, Hepatic TG (f), serum TG (g), hepatic CE (h), serum CE (i) and serum NEFA (j) contents. k, Representative H&E staining (left), Oil Red O staining (middle) and Sirius Red staining (right) of liver sections (n = 3 mice/group, 3 images/mouse). Scale bar, 100 μm. l-p, Histology scores of steatosis (l), lobular inflammation (m), hepatocyte ballooning (n), NAFLD activity (o) and fibrosis stage (p). q-s, Relative mRNA levels of genes related to hepatic lipid metabolism (q), inflammation (r) and fibrosis (s). Data are the means ± s.e.m. b, e, g-j, r, Two-tailed Student’s t-test. a, c, d, f, l-q, s, Two-tailed Mann-Whitney U-test.