Chemokine receptor down-regulation and NF-κB. Macrophages from D6-deficient mice were either left untreated (■) or were stimulated with 100 ng/mL BLP () in the presence or absence of the NF-κB blocker BAY-11 at both 3 and 30 μmol/L for 4 hours and CCL3 (A) and CCR2 (B) transcription determined by qPCR.