RT-PCR and Northern blot analyses of TM and TF mRNA in U937 cells and monocytes treated with 1,25(OH)₂D₃. Total RNA was extracted from cultured U937 cells and monocytes after exposure to 0.1 μmol/L of 1,25(OH)₂D₃ (lane 2) for 5 hours. RT-PCR analysis of TM (A) or TF (B) mRNA and Northern blot analysis of TM mRNA (C) were performed as described in Materials and Methods. Base-pair markers are shown to the left. GAPDH and β-actin were used as quality controls of mRNA.