CASP2 and Huntington disease: Male YAC128 mice and human HD patients also have specific testicular degeneration [49], a phenotype which is also not affected by the absence of casp2 (Figure 5B, linear mixed effects model, YAC128: F(1,18) = 5.70, p = 0.028; Casp2: F(1,18) = 0.10, p = 0.75).