DARPP-32 modulates the effects of dopamine on cAMP/PKA-dependent gene transcription through transcription factors of the cyclic AMP-responsive element-binding (CREB) complex (Fig. 1), and CREB dysregulation has been linked to both ADHD [38] and obesity [39]. Here, PPP1R1B is linked to obesity due to melanocortin 4 receptor deficiency.