In a different study, male Mecp2 KO mice showed hyper-reactive escape and defensive behaviors in a ‘mouse defense test battery’ assay (‘predator avoidance’, ‘chase/flight’, ‘closed-door approach’, and ‘forced-contact’ tests), despite the lack of an anxiety phenotype, as tested in the ‘elevated plus’ maze and ‘elevated zero’ maze (Pearson et al., 2015). Here, MECP2 is linked to Anxiety.