Blocking CCR5 by maraviroc28 in H mothers through pregnancy (300 μg ml−1 in drinking water) resulted in no change in male offspring anxiety-like behaviour (distance travelled in elevated plus maze; t-test: T=−1.195, P=0.246, N=10 drug, 11 vehicle), suggesting that the elevated MIP-1β level in H/F1 mothers may not contribute or more likely is not solely sufficient to programming anxiety. This evidence concerns the gene CCL4 and Anxiety.