PDE4B and schizophrenia: Regarding the underlying mechanistic role played by PDE4B in the pathogenesis of schizophrenia, Millar et al. [12] demonstrated that DISC1, another established risk factor for schizophrenia, interacts with the UCR2 domain of PDE4B and increased level of cAMP gives rise to dissociation of PDE4B from DISC1 and an increase in PDE4B activity.