Similar to the data from our cell culture models of HD, we found a ~60–70% reduction of PNKP activity in the STR and CTX of zQ175 mice, and only ~3–4% reduction of PNKP activities in the CRBL, with no change in steady-state PNKP protein levels (Figures 6A to 6C). The gene discussed is PNKP; the disease is Huntington disease.