['To investigate the effect of sonic hedgehog (SHH) on the proliferation of synovial fibroblasts (SFs).', 'The serum samples were collected from 30 rheumatoid arthritis (RA) patients, 30 systemic lupus erythematosus (SLE) patients, 30 ankylosing spondylitis (AS) patients and 30 healthy subjects. The concentrations of serum SHH were detected by ELISA. Collagen induced arthritis (CIA) were developed by type 2 collagen in Sprague-Dawley rats. The SFs were isolated from knee synovial tissues of CIA rats, and then identified by the detection of vimentin by immunofluorescence technique. Before and 72 hours after blocking SHH-glioma-associated oncogene 1 (Gli-1) signaling pathway with GANT61, the expression level of SHH in SFs was detected by Western blotting, and the proliferation of SFs was examined with CCK-8 assay.', 'The level of serum SHH in the RA patients was remarkably higher than that in the SLE, AS patients and the healthy controls. In the CIA rats, the expression of SHH in SFs in vitro was higher than that in the healthy control rats. After 72-hour treatment of GANT61 to block SHH-Gli-1 signaling pathway, the expression level of SHH protein in SFs from CIA rats was reduced, and meanwhile the proliferation of the SFs was inhibited.'] Does [ Sonic hedgehog ( SHH ) promote the proliferation of synovial fibroblasts of rats with collagen-induced arthritis ]?