The stability of behavioral characteristics of these lines allowed for exploring the genetics behind these phenotypes that led to the identification of some candidate genes of anxiety including cathepsin B (Czibere et al., 2011), arginine vasopressin (Kessler et al., 2007; Bunck et al., 2009), transmembrane protein 132d (Erhardt et al., 2011), glyoxalase 1 (Krömer et al., 2005), corticotropin releasing hormone receptor type 1 (Crhr1; Sotnikov et al., 2014) and high mobility group nucleosomal binding domain 3 (Hmgn3; Czibere et al., 2011). This evidence concerns the gene CRHR1 and Anxiety.