In this study, we demonstrate that arthritis in mice with myeloid-specific Pggt1b deficiency is driven by unprenylated GTP-bound small RHO family GTPases, which in turn trigger Pyrin (Mefv) inflammasome activation, GSDMD-dependent macrophage pyroptosis, and IL-1β secretion. The gene discussed is IL1B; the disease is arthritic joint disease.