Dose-dependent ATRA inhibition of TF mRNA expression in LPS-stimulated THP-1 cells. Total RNA was extracted from THP-1 cells exposed to LPS (10 μg/mL) for 2 hours with or without a 30-minute pretreatment with ATRA at doses ranging from 1 × 10⁻¹⁰to 1 × 10⁻⁵ mol/L. The control sample was incubated without LPS or ATRA. TF and TNF-α mRNA levels were determined by Northern blot analysis using radiolabeled human cDNA probes. Blots were reprobed with a G3PDH cDNA probe to assess RNA loading. The positions of TF (A) and TNF-α (B) mRNAs are indicated.