GRM5 and Anxiety: Homer2AA/AA manifested lower behavioral signs of a anxiety-like state within the elevated plus-maze and light-dark box tests that align with the phenotype of GRM5R/R KI mice with reduced steady state Homer binding (Table 3; Cozzoli et al., 2009; Guo et al., 2016) and GRM5AA/AA KI mice with deficient signal-regulated mGlu5 interactions with Homer (Table 3; Campbell et al., 2019; Park et al., 2013).