Neither anxiety-like behaviours nor locomotor activity showed significant differences between genotypes across multiple testing paradigms, apart from a small decrease in ambulation of C3ar1-deficient mice in the aversive central zone of the OF arena, which in the absence of a locomotor phenotype could index anxiety-like behaviour.98 This latter change, however, was not reproducible across study cohorts and was no longer observed in the same study in the core of the OF arena. This evidence concerns the gene C3AR1 and Anxiety.