SMAD5 and Huntington disease: We found that, compared with those in HD samples, RRAS2, SYNCRIP, GLO1, TWSG1, FERMT2, and TNC were upregulated in RISS-I samples, whereas HDAC7, CTSK, SUN1, RUNX1, SMAD5, CTNNB1, and ADAR were more highly expressed in R-ISS III samples (Fig. 6G).