Overall, Igf-1r deficiency had no significant effects on lifespan or grip-strength in HD mice, but on affected endophenotypes had opposite effects in male and female mice: In HD females, Igf-1r deficiency was neutral (rotarod, weight) or beneficial (delayed tremor onset), whereas in HD males had neutral (tremor onset) or detrimental effects (worsened rotarod performance and weight loss). This evidence concerns the gene IGF1 and Huntington disease.