PTK2B and Arthritis: Figure 1 demonstrates behavioral responses in the vehicle and PTK inhibitor analog pretreatment groups with k/c arthritis. The decrease in PWL response occurred maximally on the side ipsilateral to the inflamed knee 4 h in control animals and was linearly correlated with the increase in joint swelling. In the present study, similar responses were demonstrated for arthritic rats intrathecally treated with vehicle (75.3% of baseline, p < 0.01).