GDF15 and arthritic joint disease: Intraplantar injection of GDF-15 inhibited the arthritis-induced thermal hyperalgesia and mechanical allodynia (Fig. 1, J, two-way RM ANOVA, PWL: F(1,10) = 4.47, P = 0.04; PWT: F(1,13) = 4.25, P = 0.046).