GMPS and Arthritis: The IMPDH inhibitor mycophenolate (MPA), an immunosuppressant effective in arthritis and transplantation (Broen and van Laar, 2020), reduced AF647-OVA uptake in Faminp.284R and Faminp.254V splenic DCs (Figure 4H), as did the GMPS inhibitor psicofuranine (Udaka and Moyed, 1963) (Figure 4I), suggesting increased flux through GMPS, too.