Effect of inhibitors on GPR109A/HCA2 mRNA levels in RAW cells. Cells were preincubated for 1 h with thalidomide (500 μg/ml) (A), BX795 (10 μM) (B), or PTN (20 μM) (C) and LPS (100 ng/ml) for 16 h. Total RNA was isolated, and GPR109A/HCA2 mRNA levels were quantified by qPCR performed as described in Materials and Methods. The data are presented as the mean ± SEM. Data are expressed as fold increase over controls. N = 3 per group. * P < 0.05, ** P < 0.01, *** P < 0.001.