Validation of the differential expression of selected genes. hTERT-OA 13A FLS (passage 8) and hTERT-RA 516 FLS (passage 8) were plated in 100 mm plates at 60% confluence. On the second day, medium containing 10% serum was added and the cells cultured for another 24 h. RNA samples were extracted and examined by semiquantitative RT-PCR. A. The mRNA levels of HLA-DRB4, HLA-DRB3, HLA-DPA1, and ß-Actin. B. The mRNA levels of MSR1, PLA2G2A, CD36, and ß-Actin. Experiments were repeated at least 3 times and used 2 different RNA batches. Similar results were obtained.