SUPT4H1 and Huntington disease: R6/2 mice carrying a heterozygous deletion in Supt4h also showed a longer lifespan (Fig 5C) than did Supt4h+/+ animals; however, no detectable effect of an Supt4h deletion on the loss of body weight that is characteristic of HD progression in R6/2 mice (Fig 5D) was observed.