CCL2 and sarcoidosis: Using genes PSMB2 (1.95 ± 1.66; p = 0.02) and gene RPL32 (1.77 ± 1.25; p = 0.03), and gene pair PSMB2-RPL32 (1.65 ± 1.17; p = 0.02) as denominators, CCL2 mRNA levels differed between chest radiographic stage 2 and stage 1 sarcoidosis patients (Fig. 5).