PPP1R1B and Huntington disease: Some of these TRAX-sensitive mRNAs, including protein phosphatase 1 regulatory subunit 1B (PPP1R1B, the gene encoding dopamine-and cAMP-regulated neuronal phosphoprotein; DARPP-32) and brain-derived neurotrophic factor (BDNF), were shown to play key roles in HD pathogenesis.