SHH and rheumatoid arthritis: As shown in Figure 2, the expression of GLI1 mRNA, SMO mRNA, and SMO protein was up-regulated after treatment with the SHH agonist, Purmorphamine, and expression was decreased after incubation with SHH antagonist, Cyclopamine in RA-FLSs compared to the control group (all P < 0.05).