Expression of the Htr2a gene was decreased in HD mice at 8 weeks of age, when compared to their WT counterparts, in the striatum [Figure 4A; F(1,65) = 11.700, p = 0.001], hippocampus [Figure 4B; F(1,66) = 60.316, p < 0.001], and cortex [Figure 4C; F(1,67) = 30.580, p < 0.001]. This evidence concerns the gene HTR2A and Huntington disease.