We also demonstrate that the effect of EGF stimulation on the localisation of mutant huntingtin is suppressed in StHdhQ111/111 and HdhQ111/111 cells; this suppression is consistent with the inhibited kinase phosphorylation and gene expression responses to EGF stimulation in other cell and Drosophila models of HD [79,80], as well as with the delayed EGFR degradation and altered trafficking that has been observed in human HD fibroblasts [78]. This evidence concerns the gene EGFR and Huntington disease.