Figure 3: Real-time polymerase chain reaction measurement of ABCG2 expression in Group A (in which the synovium was harvested from the transitional zone between the articular cartilage and the synovial membrane at the femoral condyle) and Group B (in which the synovium was harvested from an area 5 mm medial to the transitional zone of the femoral condyle). ABCG2 mRNA expression was 1.25 ± 0.11-fold higher in Group A than in Group B (*P<0.05).