Pde4b KO mice show anxiogenic-like behaviour in theholeboard and light-dark transition tests (Zhang et al,2008), and therefore null mutation (KO) and missense mutation (Y358C) ofPde4b appear to have opposite effects on some tests of anxiety (Rutten et al, 2011; Siuciaket al, 2008; Zhang et al,2008). The gene discussed is PDE4B; the disease is Anxiety.