Chondrocyte death in cartilage layers of inflamed knee joints of p47phox-/- and wild-type mice). At day 3 after ICA induction (a) and at day 3 (b) and day 7 (c) after IFNγ-stimulated ICA. Chondrocyte death was determined in various cartilage layers of the knee joint (LF, lateral femur; LT, lateral tibia; MF, medial femur; MT, medial tibia; P, patella). Chondrocyte death was expressed as a percentage of empty lacunae. Note that without IFN-γ no chondrocytes were observed. At day 7 after IFNγ-stimulated ICA, chondrocyte death was clearly present in wild-type controls (d), whereas in p47phox-/- mice chondrocyte death was completely absent (e). Original magnifications ×400.