a, Top, representative conformations of p38γ and the ATP-binding site of p38γ, both with the inhibitor pirfenidone bound (in purple), extracted from the molecular dynamics simulations. Middle, the activation loop of p38γ is shown in teal and other relevant ATP-binding site residues are shown in light blue. Bottom, plot of distance (in Å) between the oxygen of the pirfenidone carbonyl group and the amide backbone of p38γ Met112 during the molecular dynamics simulations for the five replicas (shown in different colours). Short distances indicate binding of pirfenidone in the ATP-binding site. Spontaneous binding of pirfenidone to p38γ was observed in one out of five simulations. b, Western blot of phosphorylated Rb. 10 μM BIRB796 or pirfenidone were added 30 min before the kinase assay. Representative western blot of at least three independent experiments. c, Wild-type mice were untreated (control) or treated with pirfenidone for 10 weeks and blood concentrations of the following selected parameters were assayed: alanine aminotransferase (ALT), as a readout of hepatic injury (comparisons were made by two-sided Student’s t-test); aspartate aminotransferase (AST), as a readout of hepatic and cardiac injury (comparisons were made by two-sided Student’s t-test); total bilirubin, as a readout of hepatic injury (comparisons were made by Mann–Whitney U-test); alkaline phosphatase, as a readout of hepatic and cardiac injury (comparisons were made by Mann–Whitney U-test); creatine kinase (CK) and creatinine, as a readout of cardiac and renal injury (comparisons were made by Mann–Whitney U-test). All data are mean ± s.d. (n = 10 mice). d, Immunoblot analysis of p38γ in liver and tumour samples after AAV-Cre infection. Representative western blot of at least three independent experiments. e, Number of tumours and tumour size as analysed at the end of the experiment. Data are mean ± s.e.m. n = 10 untreated and n = 20 cre-treated mice. Comparisons were made by two-sided Student’s t-test with Welch’s correction; *P < 0.05; ***P < 0.001. f, Representative contrast-enhanced MRI results from mice 7 months after DEN injection with or without CRE-mediated p38γ deletion. The figure shows axial slices extracted from the 3D volume dataset. Arrowheads mark typical liver tumours. g, AAV-Cre-mediated deletion of p38γ protects against streptozotocin-induced HCC. Left, increased liver damage was found after streptozotocin treatment. Comparisons were made by Student’s t-test; ***P < 0.001. Right, tumour size as analysed at the end of the experiment. Comparisons were made by one-way ANOVA coupled to Bonferroni’s post-test; *P < 0.05. Data are mean ± s.e.m. n = 10 untreated and n = 20 AAV-Cre-treated mice. In the western blots, each lane corresponds to a different mouse. Source data