Fig. (3) Kinetics of JNK pathway activation in joints of mice with passive K/BxN arthritis and collagen induced arthritis (CIA). The time course for JNK activation differs in two models of arthritis. Passive K/BxN arthritis is dependent only on innate immunity, while CIA involves both adaptive and innate immune mechanisms. (A) Clinical arthritis scores for passive K/BxN arthritis. (B) Clinical arthritis scores for CIA. (C and D) Phosphorylation of JNK and MKK4 were evaluated by Western blot analysis for passive K/BxN arthritis and CIA, respectively. Note that the time course for arthritis severity compared with JNK activation as well as JNK isoform activation differ in the two models [84].