Furthermore, we noted lower TF activity of MYC in the aged HD relative to the aged WT hGPCs (Fig. 5e), which may highlight the intrinsically greater capacity of WT cells to compete; this was congruent with our earlier observation that aged WT hGPCs respond differently than HD hGPCs when challenged with newly engrafted WT GPCs. This evidence concerns the gene MYC and Huntington disease.