CtsB inhibition decreases the fibrogenic potential of HSCs. A, α-SMA and Col1A1 protein levels, and B, proliferation rate after CtsB inhibition with Ca074Me (20 μmol/liter, 48 h, added every 24 h from day 5 to day 7), in ASMase+/+ and ASMase−/− HSCs. Data are mean ± S.D. (error bars), n = 3. *, p ≤ 0.05 versus ASMase+/+ control HSC; #, p ≤ 0.05 versus respective controls.