HOXB8 and trichotillomania: It is this latter subpopulation of microglia that, when dysfunctional, results in the acquisition of chronic anxiety and obsessive-compulsive spectrum-like behavior (i.e. either genetic disruption of Hoxb8 or specific ablation of this microglial subpopulation in mice results in chronic anxiety and trichotillomania-like pathology) (Nagarajan et al., 2018; Trankner et al., 2019).