Reduced Tph2 expression is associated with an impulsivity‐, aggression‐, and anxiety‐related phenotype combined with alterations in prefrontal cortex, anterior cingulate, and amygdala (Coccaro et al., 2011; Ko et al., 2018; Lesch et al., 2012; Mark et al., 2019; Waider et al., 2019). Here, TPH2 is linked to Anxiety.